Websites:
https://sheldonbrown.com/ – Well organized information about old bicycles. Indispensible if you are doing a fixie conversion of a vintage bicycle. Sheldon Brown the man died in 2008, but the site is still maintained.
https://peter-wiegel.de/ – Free fonts, some very interesting historical ones, my favicon is Altenglisch.
Youtube Channels:
https://youtube.com/@BadObsessionMotorsport/ – I have following since episode 9 of Project Binky, there really is nothing like it on the internet.
https://youtube.com/@KnitFactoryImpl/ – Knitting machines and information on how you can hack them.
https://youtube.com/@Clickspring/ – I have been watching Clickspring almost since its inception, the quality of fabrication is very high, I particularly like his videos on reverse engineering ancient clockmaking techniques.