Arnold - A NICE FTP site with a collection of games, ROMS, etc!!!
Bo Zimmerman's site - Probably the best resource on all Commodore models and equipment. Lots of Pictures!
Ray Carlsen's Site - The best collection of repair articles and how-to's on most hardware issues.
Jim Brain Innovations - Home of the uIEC, Rom-el, and JiffyDos.
Robert J. Long's Commodore Product Source List
VICE Homepage - PC emulator for Commodore machines.
openCBM - (aka: CBM4WIN) allows access to CBM drives from a PC.
JP Products By Mail - Joe sells 1581 Drive kits!
Lemon 64 - A forum with lots of info, and some drama too.
DLH's Commodore Archive - Scans of magazines, books, manuals, etc.
RetroHackers - A good source of info on what people are doing with the 64NIC+ and other harware/software projects.
Style - One of the many Demo groups.
Leif Bloomquist's Commodore page - Home of Netracer and Artillery Duel.
Commodore BBS Outpost - List of IP based BBS's you can connect to with a Ethernet enabled commodore or VICE.