- Matt3o's "Book": How to Build a Custom Keyboard (more or less a series of long and very informative blog postings under a Creative Commons license)
- The 40percent.club Blog
- Keebfolio, a list of open source keyboards, tutorials and similar stuff.
- Open Source Mechanical Keyboards and where to find them
- List of PCB Manufacturers and laser cutting services in the wiki of joric's Crkbd/Corne variant called jorne.
- ai03's PCB Designer Guide
- Keyboard PCB Guide
- The 40percent.club Blog about:
- The Goldfish, an open-source USB-C Pro Micro clone. (Geekhack thread)
- Elite-C: at CandyKeys or at NovelKeys
- PJRC Teensy (multiple variants): at Maker-Shop.ch, at Pimoroni
- SparkFun Pro Micro (5V): at Pimoroni
- Blue Pro Micro clone: at CandyKeys or at KeyHive
- QMK Proton C: at OLKB, or at 1UP Keyboards or at mykeyboard.eu