Depends how experienced you are with the command line and how comfortable you are having access to system files (and, consequently, having the ability to FUBAR your whole computer).
@ excess: I had some training in Unix command line a couple years back, but I don't really remember too much from it.... As for the FUBARing of my computer...lets just not go there :) lol simpler is better, especially because I can't afford to put too much time into this
@ finch: Any good sites to get it from? (or just torrent, Im guessing)
Well then Ubuntu does sound like a good idea. There are other simple distros, but Ubuntu really is the cream of the crop, as I'm sure you already know.
Nowadays most Linux distributions are the same thing. You only see differences in desktop environment, applications, window managers etc...
The main kernel of the Linux distribution is the same throughout. If your looking for a really small, lightweight distribution for beginning to learn Linux bash commands then try DSL (Damn Small Linux). You can download it from here: http://www.damnsmalllinux.org/download.html Also if you want a guide for learning linux then ty this: http://www.brunolinux.com/
If you want to try these distros virtually first then download VirtualBox from http://www.virtualbox.org/. Then download a virtual version of the distro from here:
yes!, i recommend Ubuntu, it has improved a lot with the last distro, the installation is easier than ever, it can be installed/uninstalled as any Windows Program, while running Windows, of course. So, forget to mess around with the partitioning!