Rebernik is right...linux is a very powerful operating system. The reason for this is that you can customize anything about the OS....and i mean ANYTHING, as you have the source code for it all.
The pros: full power over your system, really secure, a lot faster than windows, just about everything is free (rarely will you pay for any software...only when its big time software such as VMWare which is a superb OS emulator)
The cons: takes time to learn.
Basically, if you are just a person that wants to have an OS loaded and ready to go, linux probably isnt the way to go....its not nearly as easy as windows. Depending on which distribution you choose, there will be different learning curves.
There are easier to use distributions. These come with loads of bells and whistles: Red Hat (Fedora now), Mandrake, Debian
And there are harder distros such as Slackware.
Note: its a good idea to research how popular the distro is, because the more popular, the easier it is to find help if you need it....all the ones i listed are popular distros.
With linux you could go anywhere from a complete command line OS to a full bells and whistles OS like windows. But just remember, dont even bother if you aren't willing to take the time to learn it. And always check out the distros website.
If you do plan on installing linux, test your system out by downloading Knoppix or Topologi. Knoppix boots the OS off a CD, so you never have to install, and Topologi creates a virtual OS on your system by making a file in windows that acts as a Linux partition. NEITHER WILL INTERFERE WITH WINDOWS.
I will be installing Slackware on a new hard drive in a couple weeks...(i got plenty of time to learn

)
Good place to check out too is
www.tomshardware.com, and look for the linux migration article.
Hope that helps
