I'm learning iPhone development and a friend will be doing the graphics/animation. I'll be using cocos2d most likely (if that matters).
My friend wants to get started on the graphics, and I don't know what image resolution or dpi or formats are recommended.
This probably depends on if something is a background vs. a small character.
Also, I know I read something about using @2x in image file names to support high res iphone screens. Does cocos2d prefer a different way? Or is this not something to worry about at this point?
What should I know before they start working on the graphics?