If you are diving into Linux, follow the paths outlined above. Ubuntu is the most user friendly, and there is a great helpful community of people willing to help noobs. Forums, IRC #channels, mailing lists, etc. Advanced linux users use Debian or Gentoo. I also recommend learning BSD Unix, something like OpenBSD. "Advanced" linux users have difficulties learning/adjusting to it, so it is not for you, until you have experience
Trcx was not joking when he said BackTrack forums are not noob-friendly. I used to hang out in their IRC channel and noobs get roasted when they ask dumb questions, or if they are lucky, ignored. I have seen op BP ban people just because; bc he didnt like something they said, bc they annoy him in some way, bc he was bored, etc
As an alternative, you can install BackTrack inside a VM on your Windows machine. Google "backtrack virtualbox" to get step by step instructions on how to set that up.