As one who traveled this route more than a year ago, I've gained a lot of information about Windows users checking out Linux. Rather than diving into a full scale distro such as Red Hat, Mandrake, or Slackware, I would suggest trying out one of the CD based distros. I recommend downloading the Morphix Heavy GUI ISO, burn it to disk, set your Bios to first boot from cdrom, put the cd in and boot. You can download it from here...
http://morphix.sourceforge.net/modules/mydownloads/
A complete working O.S. of Morphix-Linux will boot for you to check out that will pose no danger to your Windows XP. After a thorough examination, if you think Linux might suit your needs, Morphix comes with a text based installer, (Fdisk) that's pretty easy to install Morphix to your hard drive.
I would listen to what Sky and Troodon have to say about all this before making a decision though. Let me know if I can help further.
