I use Dvorak. I basically learned it by printing out a copy of the keyboard layout and posting it in front of me, next to my monitor. (I also made little sticky labels to put on the keys so I could look down, but once you've gotten used to things you don't need those anymore.)
I remember reading a lot that the key to switching over is to make the switch totally and immediately. To be honest I don't remember if I did that or not (I think I tried to, because I think I started at the beginning of a weeklong vacation from school, but if you have to do any typing on public computers then you'll probably be stuck using QWERTY then anyway), but after a few months I felt pretty confident in using Dvorak all the time. It feels like a long time, though, especially because you'll be so much slower in Dvorak at first. I think there might actually be better keyboard layouts out there (at least in terms of finger distance traveling and whatnot), but as far as alternate keyboard layouts go, Dvorak is the best supported.
One downside: for those times that you have to go back to using QWERTY and can't help it, you'll probably find that (especially toward the end of the transition period) you'll keep thinking in Dvorak--or at least I do. I'm definitely faster using Dvorak, but that might be because my QWERTY skills have gone down some. Bascially, the problem reduces down to the fact that you have to deal with everyone else still using QWERTY and not supporting Dvorak, but I don't regret having switched.