I agree, You can perform a dual boot requiring you to select xp/linux during start-up. You can try out most Linux distros with a live CD that will allow you to boot from the CD and test drive the distribution with limited capabilities (unless you know what your doing). I also agree that UBUNTU is the easiest distro to use when starting out and arguably one of the best in general. It has good support and has good tools to help it run along side windows if you need it. There is allot of information take a look on Google. One thing is would say is don't give up on Linux. There is always good help available and once you have it working the way you need it is VERY reliable and nice to use. Good luck.
Ruffles