Just a very short message - I've dabbled in linux before, but tonight I downloaded a free version of Knoppix - click here
and burnt it to CD - Basically it's Linux but on a CD, so you can run it from booting up with nothing installed to your computer - it's all stored in the memory! In all honesty, i've been most impressed with this version, there's loads of software included, and as long as you have a memory stick (which auto detects) you can save your work etc.
You get Open Office and loads of other software, all my peripherals automatically detect etc.
In fact it's the most painless way to try linux out. Logging off and rebooting my computer (removing the cd from the drive) restores win xp pro - give it a go, you may just like it!