Drawn & Quarterly's 40% - 50%-off sale AND Top Shelf's $3 Online sales. These are both great ways to sample a range of great experimental and independent comics without spending a lot of money. Both publishers showcase a diverse range of pretty amazing work, so check out their rosters and, while you're at it, take a look at their submission guidelines for submitting your own!
Note: Top Shelf also features a whole page of links to interviews on other sites with some of the artists they publish. James Kochalka, Allen Moore, Lilli Carre, Jeffrey Brown, Renee French, and more. Drawn and Quarterly also features in-depth bios of its artists.