Electronics

• https://www.edn.com/designcenter/automotive/: post, designs, ideas
• https://www.electronics-lab.com/: tools, posts, download links
• https://ultimateelectronicsbook.com/: online book
• https://www.rapidtables.com/electric/index.html: symbol and formula reference

CAD Tools

• https://www.circuitlab.com/: circuit lab and schematics
• https://easyeda.com/: PCB design
• https://www.tinkercad.com/: online autodesk tool
• https://www.kicad.org/: free, open source

Libraries

• https://chris-pikul.github.io/electronic-symbols/: SVG, PNG, JPG downloads