Self-Publishing
Lulu.com Great site for self-publishers. A little pricey for full color but perfect for samples.
Moo.com Fun printer of mini business cards etc.
Ka-Blam Comic book printer. Nice quality, no set-up fees, but can take a while to get books so give yourself plenty of time to order before you actually need books.
Busybeaver.net Good site for promotional buttons.

Video Game Sites
Retromundi.com Home of online retrogaming competitions and emulation!
netives.com (I like the Marbles game best!)

Schools of Cartooning
The Joe Kubert School of Cartooning and Graphic Art
The Center for Cartoon Studies