hi,
i am using linux ubuntu at this moment, and i am very pleased of it.
i used fedora core once but i didn't like that alot.
and yes, there are many operating systems build on linux.
i can really advice ubuntu, it is i believe the most user friendly linux based os at the moment. installation is very easy, and lots and lots of hardware is supported.
if you want to try it, it is perfectly possible to run windows and linux on the same machine.
but i you start experimenting with it backup all your data very well. read the topic big problem in the winxp forum to see what can happen if you get lost
Jan.