Here's some hard 'n fast Linux tips.
Mandrake 10.1 doesn't install correctly over hidden Windows partions. For a dual-boot or multi-boot Linux distro, this is not the one to use.
Debian is by far the best distro I've survey'd (RedHat, Debian, Mandrake, TurboLinux). There's a reason it's the basis for so many LiveCD versions. Debian can install to a single partion if desired.
Once familiar with UNIX/Linux, you'll find working without things such as Emacs, regular-expressions, and scripting to be a chore.
LiveCDs are the way to go to get a feel for Linux. I personally like the look and feel of Morphix, but Knoppix et al are all a good way to survey different things. This is, of course, if you're still addicted to the mouse and like pointing and clicking.
I don't have anything against RedHat, but it's not my fave for whatever reason. I think Debian has an edge in managing package dependencies. Debian comes with thousands of packages, plus it doesn't need a GUI to install. The consideration is that not all packages come in Debian packages. However, it's possible to install packages on Debian without using Debian packages, so I'm not sure that's a downside.
Hope this helps.
Sean