Ok... yeah. If you want to try Ubuntu, I can only say, go for it. Its a great OS, and if you aren't terribly into gaming it will be perfect for you.
That is if you don't mind getting to know a whole new way of working with an OS, sure Ubuntu is quite easy to use, but still there are certain things you oughta know. Photoshop will work, but only v.7 and only under WINE.
You could of course always use GIMP (which I loathe, but hey, to each his own.)
If you need any help, I will assist you as much as my knowledge allows.