These are some links to resources I have found useful while building my system.
Forums
Muff Wiggler – https://www.muffwiggler.com/forum/
Electro-Music – http://electro-music.com/forum/
Social Media
Pusherman – https://www.facebook.com/groups/1677419455833872/
Pusherman’s Eurorack DIY Noobs – https://www.facebook.com/groups/1716364098644678/
Eurorack DIY – https://www.facebook.com/groups/436675570022014/
Synth DIY – https://www.facebook.com/groups/synthdiy/
PCBs/Panels
Pusherman – https://pushermanproductions.com
Thonk – https://www.thonk.co.uk
Modular Addict – https://modularaddict.com
Frequency Central – http://www.frequencycentral.co.uk
Barton Musical Circuits – http://www.bartonmusicalcircuits.com/synthstuff.html
Components
Mouser – https://www.mouser.co.uk
Arrow – https://www.arrow.com
Farnell – https://www.farnell.com
Other Sites
Niklas Rönnberg – http://familjenronnberg.se/~niklas/diy/eurorack/noise/
Paper Synthesizer – http://paperpcb.dernulleffekt.de/doku.php?id=paper_synth:paper_synth_main
SyntherJack – https://syntherjack.net