I can relate. I’m a programmer, not a graphic designer (for the most part, at least). Anyways, the first place you might want to check out is OpenGameArt. You can find a lot of game resources there including soundtracks, sprites, sound effects, 3d models, etc. Plus, it’s all free.
You can also look here:
http://www.spriteland.com/
http://untamed.wild-refuge.net/rmxpresources.php?characters
Then again, the best thing you can do if you are making games is either get good at making graphics (using something like Gimp or Inkscape), or having a friend who is good at graphics join your team.