Learn to draw pixel art
A written 10-step tutorial by Derek Yu on how to draw pixel art. Very informative and easy to follow.
Read the tutorial on Derek's blog, here:
Derek Yu created Spelunky which is one of my all time favorite games, which also makes him one of my favorite game developers.
There's a bunch of other high quality articles on his blog which I also advise you to check out. Some examples include his post mortem on Spelunky or his article about the design problems with Earthworm Jim.