judging from your avatar, you have a digital camera?
it should come with image editing software (most likely Photoshop LE) right?
actually for photos, you would mostly need 2 tools from Photoshop - Curves and Unsharp Mask. Most of the time u will be mucking with these 2, esp Unsharp Mask. u don't really have to learn all of photoshop to edit your images. (knowing much more is good though. there's more than 1 way to do things in photoshop)