"skill" tag on learn.sparkfun.com

A wide variety of technical tutorials on various EE related skills.

Soldering is Easy

Comic book that goes over the basics of soldering that has been translated into quite a few languages.

Uses of Different Soldering Iron Tips

Covers what all those different soldering iron tips are good for.

How to design a motherboard for your electronics project

Introductory tutorial on Schematic & PCB design

Khan Academy - Electrical Engineering

Non-profit learning platform with a full course on electrical engineering and related topics.

NEETS (Navy Electricity and Electronics Training Series)

U.S. Navy Non-Resident Training Course Material.

NPTEL

Has all free engineering courses including electronics, electrical and communcation engineering.

Udemy courses related to Electronics

Top paid courses available on Udemy.

Coursera courses related to Electronics

Includes some free courses that provide e-certificates on completion.

Electronics textbook

Text covers design and function of electronic circuits and components, DC analysis, and AC analysis.

Student Handbook

Language used in this book easily understandable covers evolution, fundamentals, diode, rectifiers, transistors and its applications, SCR, DIAC and TRIAC.

Electronics circuits and systems

Quality free e-book covering all topics under circuits and systems, highly recommended for conceptual understanding.

Lessons In Electric Circuits

Free high quality textbooks and worksheets with emphasis on theory, simulation, and the socratic method.

Ultimate Electronics: Practical Circuit Design and Analysis

Free online book with interactive schematics & simulations by CircuitLab (under development).

Berkeley EECS

Comprehensive EE & CS course website archives.

Dr. Jacob Baker

Courses and tutorials, professor at The University of Nevada, Las Vegas.

Dr. Abraham

, Dr. McDermot, and Dr. Valvano - Courses materials, professors at UT Austin

Inkscape Electric Symbols

Circuit Drawing Symbols for Inkscape

Tabula

Extract tabular data from a pdf, very useful for extracting pin tables or part characteristics from datasheets.

WebPlotDigitizer

Extract data from plots, charts, etc., very useful for getting part performance curves from datasheets.

WaveDrom

Create waveforms and timing diagrams from a JSON description file.

tscircuit

Open source EDA package for schematic and PCB design using React

LTspice

The industry standard free SPICE circuit simulator from Linear Technologies. Also see the unofficial LTwiki and Group.

ngspice

Open source SPICE circuit simulator.

Circuit JS/Falstad

Free, open source online simulator with electron flow visualization (rewrite of original Java applet by Paul Falstad).

EveryCircuit

Free to try online, visual, interactive circuit simulator for simpler circuits.

Qucs

Open source, cross-platform, non-SPICE-based circuit simulator, with with S-parameter and Harmonic Balance capability.

Qucs-S

Open source fork of Qucs using SPICE for simulation.

QucsStudio

Free, closed-source, Windows-only fork of Qucs with a similar interface, new engine, and more features.

Open Circuit Design Software

Open Source, full EDA suite chip design suite, focused on keeping up with commercial tools.

TINA-TI

Exclusive DesignSoft-TINA build for Texas Instruments, bundled with Texas Instruments Models.

CppSim

Free, open source circuit simulator that leverages the C++ language to achieve very fast simulation times.

Scilab with Xcos

Free, open source numerical computing alternative to MATLAB. Xcos provides Electrical System modeling capability similar to Simulink.

iCircuit

Easy to use electronic circuit simulator, its advanced simulation engine can handle both analog and digital circuits and features realtime always-on analysis.

Micro-Cap

Professional-grade mixed signal simulator with wide variety of interactive simulation types.

GeckoCIRCUITS

Open Source Power Electronic Circuit Simulator. GitHub Project. Direct download link due to broken website.

Proteus

PCB Design and Circuit Simulator Software.

Verilator

Free, open source Verilog compiler. Test benches are in C++ or SystemC. Very fast, but limted to 2-state, cycle-based simulation, and synthesizeable code only.

Icarus Verilog

Free, open source verilog interpreter. Test benches are in behavioral verilog. Simulation is 4-state, and event-based.

Tracespace Viewer

Gerber viewer that lets you inspect the individual layers as well as the board preview.

Gerblook

Online Gerber viewer powered by Gerbv.

Mayhew Labs 3dpcb

3D Gerber viewer.

CircuitPeople

No frills 2D layer viewer for Gerbers, without the excessive processing.

Stackrate Viewer

Easy to use online gerber viewer with trace hovering and measurement tools.

Gerbv

Excellent Gerber viewer for Linux and BSD.

KiCAD Gerbview

The KiCAD gerber viewer.

GC-Prevue

Commercial with free version. Can handle some gerbers better than Gerbv and KiCAD.

ZofZPCB

FREE 3D Gerber Viewer.

KiCAD Gerbview

The KiCAD gerber viewer.

Eagle

One of the most popular EDA packages due to it's (board size restricted) free version.

DesignSpark PCB

Gratis EDA package without restrictions, sponserd by RS Components.

Altium CircuitMaker

Free package from the maker of the go to pro software.

gEDA

Another open source package, good for people that like scripting and makefiles, Linux and BSD only.

DipTrace

Quality Schematic Capture and PCB Design software with (pin and signal layer restricted) free version.

LibrePCB

A new, powerful and intuitive EDA tool for everyone, cross-platform and GNU GPLv3.

Horizon EDA

A free and open source EDA tool with the focus on shortcut operation.

EasyEDA

Easy to use with both browser based and cross platform app versions. Integrates LCSC and JLCPCB component catalogs with 3D models.

Altium

PCB Design Software & Tools.

Proteus

PCB Design and Circuit Simulator Software.

Xesscorp's list of KiCad 3rd party tools

Tools made by others to augment the KiCad PCB EDA suite.

Contextual Electronics' Shine on You Crazy KiCad

Beginner video tutorial that gets you to a manufactured board as quickly as possible.

Contextual Electronics' Getting to Blinky Tutorial

A more comprehensive beginner to intermediate video tutorial.

KiCad.info Forums

User discussion and help forum.

Keyboard PCB Guide

Comprehensive written tutorial that takes you through creating a keyboard PCB.

Cheatsheet

(also in landscape) - Short PDF that goes over the menus and keyboard shortcuts for the most common operations.

Footprint Collection

Collection of all the KiCad footprints available online and some scripts to manage them.

InteractiveHtmlBom

A html BOM generation tool for manual pick and place.

KiBot

Generate the fabrication and documentation files for your KiCad projects easily, repeatable, and most of all, scriptably.

Awesome KiCad Projects

Curated list of open source hardware projects whose PCBs are designed in KiCad.

List of ULPs everyone should know

Adafruit Eagle Library

SparkFun Electronics Eagle Libraries

Altium Designer Libraries

.IntLib and .PcbLib of electronic components from different manufacturers.

PCBShopper

Comparison service for quite a lot of different PCB batching and assembly services.

OSH Park

Low cost PCB batching service with high quality boards with a signature purple silkscreen.

Aisler

Affordable quality circuit boards made in and shipped from Europe (Germany).

Dirty PCBs

Low cost PCB batching service that prides itself on its "dirty" quality.

JLCPCB

Low cost PCB batching service with inhouse low cost SMT service.

PCBWay

Low cost PCB batching service with PCBA, CNC and 3D-Printing services.

Octopart

Probably the most well known part search engine.

Findchips

Part search from Supply Frame.

Parts.io

Another search engine from Supply Frame geared towards discovering new parts.

Electronic Component Search Engine

Free access to schematic symbols, PCB footprints and 3D models.

Yoo Need One - SMD Marking Database

Surface Mount Device (SMD) component marking database.

JLCSearch

Find the most popular in-stock JLC components for different categories

Kitspace

Project sharing site that helps you buy parts and re-build projects. Open source and developed by yours truly.

Hackaday.io

Social site for sharing projects from the popular blog.

Hackster.io

Another social site for sharing projects. Is well organised by platform, topic and product.

InventHub

Git-based project hosting and collaboration platform for hardware development.

CADLAB

Another Git-based project hosting and collaboration platform for hardware development.

Eyrie

For viewing Eagle and KiCad designs online.

WikiFactory

A project hosting and collaboration platform for product development. Filter for "electronics" for more electronics related projects.

Instructables

A social site for sharing projects. Filter for "circuits" for more electronics related projects.

PartsBox

Web service to manage your part inventory with a nice user interface and Octopart integration.

Part-DB

Another open source web service for managing part inventory with a permission system and a good barcode generator.

InvenTree

Open source web service for managing part inventory with parametric search, extensive API and plugin system

SnapEDA

Parts library with free symbols & footprints. (Compatible with Eagle, KiCad, Altium, OrCad, Allegro, etc.)

Language PCB

Syntax highlighting for various PCB formats.

NinjaCalc

An embedded engineering calculator toolbox for doing calculations in a breeze.

Saturn PCB Design Toolkit

The Saturn PCB Toolkit is the best freeware resource for PCB related calculations you can find.

KiCanvas

An open source online viewer of KiCad schematics and boards.

Sparkfun

Retailer and designer of open source electronics development boards and other equipment and materials with excellent accompanying tutorials.

Adafruit

Another retailer and designer with excellent selection and tutorials.

Tindie

Marketplace for electronics makers to sell low volume batches of their own designs.

Hackaday

Probably the most popular blog covering electronics and hardware hacking with a whole staff of writers.

bunniestudios.com

Andrew 'Bunnie' Huang covers hardware hacking, open hardware, manufacturing and more.

Bald Engineer

Project logs, tutorials and articles about electronics and embedded software by James Lewis.

Rheingold Heavy

More project logs, tutorials and articles about electronics and embedded software, these ones by Dan Hienzsch.

Hackster.io

Another blog covering electronics.

Dangerous Prototypes

Blog about open source hardware projects and interesting app notes.

N-O-D-E

Blog about DIY electronics, hardware, and technology.

EEVBlog forum

Probably the largest and most active forum to discuss Electronic Engineering topics.

/r/electronics

and /r/ECE are the two most active sub-reddits for EE topics.

/r/askelectronics

Sub-reddit dedicated to help on electronics topics.

Electronics Stack Exchange

Question and answer site for electronics running on the popular Stack Overflow service.

EEVBlog beginners forum

Good place for beginner questions, other sub-forums on EEVblog should be suitable for questions on more advanced topics.

The Amp Hour

Off-the-cuff chat about electronics with Chris Gammel and Dave Jones (EEVBlog), often with guests

Embedded.fm

Christopher and Elecia White discuss embedded systems development and much more, often with guests.

The Spark Gap Podcast

Covers a specific EE topic each episode, sometimes with guests.

MacroFab Engineering Podcast

Weekly podcast where Parker and Stephen from MacroFab discuss EE topics and industry news.

The Engineering Commons Podcast

Covers general engineering topics from mechanical to electrical.

EEVblog

One of the earliest and most successful YouTube channels where Dave Jones does teardowns, tutorials and more.

BigClive

YouTube channel about teardowns (including dangerous products), circuit reverse-engineering and tutorials.

ElectroBOOM

YouTube channel that debunks and explains EE topics with a lot of comedy thrown in.

Micah Scott

Video logs of reverse engineering and re-purposing consumer electronics hardware in creative ways.

Afrotechmods

Tutorials on electronics projects, often suitable for beginners as well.

The Signal Path

Very in depth teardowns, repairs and reviews of lab equipment and prototyping products.

w2aew

Excellent tutorials about basic and complex analog hardware.

Mr. Carlson's Lab

Teardowns, repairs and restorations with an emphasis on classic electronics gear.

GreatScott

Electronics tutorials, projects and how to's.

Julian Ilett

Buys cheapest electronic modules he can find and tries to do useful things with them.

MikesElectricStuff

Teardowns, large lighting projects, xrays and more.

Ben Eater

Series of videos on building an 8-bit computer on breadboards with excellent explanations of all the sub-circuits.

Robert Feranec

100+ Hardware design tips and tricks. Videos about Schematic design and PCB layout.

Strange Parts

YouTube channel about electronics, manufacturing, making, world travel, living in and making things in China.

Analog Circuit Design

Analog Circuit Design by Prof. Ali Hajimiri, Caltech.

AdaBox

Curated Adafruit products, unique collectibles, and exclusive discounts. All delivered quarterly.

HackerBoxes

A monthly surprise box which includes projects, components, modules and tools.

GrabCad

Community supported database of 3D models with a large number of electronic component models.

3D ContentCentral

Website dedicated to 3D models of parts (requires login).

PwnKitteh/InsanelyCheapElectronics

A list of cheap electronics from China, that you can use in your projects.

PCB/EDA software list on the EEVblog forums

A much more comprehensive list of all the software tools available.

intajay/open-electronics

Another GitHub list: resources for Electronics Enthusiasts and Hardware Hackers.

Vitorian/awesome-fpga

Awesome list of FPGA resources.

cajt/list_of_robot_electronics

A GitHub list of resources, projects and products for robot electronics.

embedded-boston/awesome-embedded-systems

Awesome list of embedded programming resources.

TCAD Central

List of Technology CAD (TCAD) software and resources from the maker of DEVSIM.

Awesome Lattice FPGAs

A curated list of awesome open-source FPGA boards.

TM90/awesome-hwd-tools

A curated list of hardware design tools with a focus on chip design.

delftopenhardware/awesome-open-hardware

Helpful items for making and learning about open source hardware projects.

upb-lea/awesome-open-source-power-electronics

Open source software list specialized on power electronics.

Complete EE Course

دورة الالكترونيات العملية

Complete Digital Electronics Course

دورة الالكترونيات الرقمية

professional Electronics Design

دورة التصميم الالكتروني المحترف كاملة

professional PCB Design

دورة تصميم اللوحات المطبوعة (PCB)