I'm still learning myself. There's still so much that I have to get the hang of. If you look for tutorials around DA, I'm sure they could help you out (I don't use tutorials for manips, though. I just do them on my own)
I've never used gimp before, so I don't know anything about that. But if you're good at that, then keep at it Hope you'll have enough for them, because they're really neat programs!