I want to program my first iPhone game, and a heard about Cocos2D. I downloaded it but...I don't know how it works. I've read a few tutorials but I still don't understand it. Probably because I don't know much Objective-C programming yet...can anybody explain to me how it works? Thanks in advance !
Did you have any questions in particular? I found it to be pretty intuitive as far as game engines go. It has all the features you'd expect in an engine, regardless of language. It's actually a port of a Python library, so you can check that out -- maybe it will make more sense: http://cocos2d.org/
Get comfortable with Objective-C first, otherwise it's like learning to fly your fighter jet and fire the gun/missiles all at once. First things first. But when you are ready, this is the best getting-started tutorial I've seen; after you have it working, trying getting a sprite to move around, adding animation frames, etc. Monocle Studio's Introduction to cocos2d iPhone