Screen capture on aluminum macbook

I tried the answer on the FAQ but it didnt work

: Where's my print screen button, how do I take screenshots?
A: Shortcuts to capture a screen or part of the screen:
Apple+shift+3 - full screen

Ok...so does OS X have an equivalent of MS Paint we can paste a screenshot into? And btw are there any skinning programs for Macs like there are for windows XP? IE alienguise from alienware, windowblinds, anything like that?