So Itch.io doesn't like it when you put a bunch of links on one page! So I moved the list here, just some stuff from my bookmarks. Will be asking the team for more resources to grow the list, and hope others post stuff here to help as well!

https://erikhoudini.com/zine_rack/resources

This jam is an excellent idea! As far as resources go, Discmaster is pretty great for searching / pulling all kinds of obscure material/imagery from a massive archive of old CD-ROMS, clip art disks etc:

https://discmaster.textfiles.com/