Your best bet would be to read up on it yourself. Linux is based on Unix, whereas Windows is based on... I'm not sure. MS-DOS?
Linux is almost always free to get, and almost everything that can be done on Windows can be done on Linux, if not everything. (There are different "flavors" or forms of Linux, such as Ubuntu, Red Hat, Knoppix, etc.)
Linux, though, is harder in that it offers users much more freedom. You can do anything you want on a Linux system, and so you have to really know what you're doing.
Me, I'm fairly new to Linux, but I already like it a lot more than Windows. As long as you're willing to put some work into it, then you'll like Linux, too.
(As for a flavor/form of Linux to choose, I'd suggest trying out Ubuntu, first. It's one of the more popular and easy-to-use flavors of Linux.)
Linux is just another OS,one being better than the other is immaterial.
Puppy linux is a good place to start especially if you want to try it out as a live cd as it as a small download,bear in mind tho the performance of a live cd is not like as if you installed it,it will be less in performance
For Which distro to use i agree with "kajnrig" as ubuntu can install it automatically or as a normal install to add/remove of xp,it is also a live cd in that once burned to cd pop it in drive & reboot,Kubuntu is the KDE version & more windows like sort of
There are two or is it three versions of linux one being Gnome the other KDE & Debian,use google to find out the main diff
Distro watch is where you can get a list of all linux OS's & download them
