i started off with paintshop pro and photoshop 7.0...those are pretty good versions for beginners and I've gottin pretty decent in the last couple months... try starting out with one of those before usign photoshop cs2 and googling some good tutorials...also it is pretty complicated in the beginning but dont give up...i've gone over the same tutorial a few times just to get it right on how to do something, sooo yea...msg me if you have any other questions
Photoshop is up to CS3 now I believe. Really there is no reason to train up for it as the best way to learn something is to use it extensively. If you want some guides, as well as CS3, go to thepiratebay.org. CS3 is in the programs top 100, and I'm pertty sure there are a few guides on it in the text downloads. Simply use the search for Photoshop and a bunch of guides should pop up.