i don't really understand looking at PSD's, i see what the layers are and stuff but it doesn't tell me what the person did, unless i'm not clicking on something.
What you do is hide all the layers(click the eye) and then make them visible one by one, and try to recreate what the person did. It's much easier once you have a good grasp of the controls in PS/GIMP.
yep, maybe look at some tuts on the basic tools and what they do for PS/GIMP(which ever you use) then start using psd's. psd's are just tuts without any step by step pictures -- you should know what to do.