If you've never tried Linux before, it's not one of those things you want to just jump in and get started on. It's somewhat like buying a car. If you know somebody who's been with Linux for a while (and you trust them to speak to you without babbling jargon) consult with them. There are many great tutorials online too. When you get stuck on a hitch, there's almost always a tutorial on your specific problem.
Getting Started
That said, Fedora isn't a beginner's OS. If you want to get your feet wet, start with Ubuntu. Better yet, Linux Mint which has its own little tweaks here and there, as well as resembling Windows more concerning behavior.
If your computer is strong enough, run something like PortableUbuntu or VirtualBox to get started. If not, install Linux onto your computer using either Wubi or Mint4Win. To use those, just download and burn the appropriate disc and insert the disc while still running Windows. Again, like buying a new car, it's better to get a feel for it before you splurge and buy into it. Even when your old car is barely drivable anymore :-).
Installation
If you feel like you want to go full-on with Linux (which shouldn't be too quick—take your time to look around, create a backup as well as a backup plan in case of screwups) and you don't have any data on it, just burn a CD and select "Use Entire Disk" choosing the partitioning—there's no real "uninstalling" of Windows, just wiping it off the drive. But before it does any actual wiping, there's a Migration Assistant that'll copy off your data and settings for cross-platform programs like Firefox. Make a backup anyway.
But if you do have some data, and you went with Mint, Mint has a wonderful backup utility called MintBackup that'll backup your data (everything important, i.e. data and program settings is all in the same folder, unlike Windows and the registry) and even a list of programs you have installed. You can backup your stuff onto a flash drive and restore it after install.
Tips
I wrote a few tips here about stuff on Ubuntu.
One thing I would add though, is don't be afraid to sound like a total n00b. Ask questions on the Ubuntu or Linux Mint forums. They have appropriate forums for um, those who want to get started. And the ever-wise, "Don't be afraid to ask questions!"
1I think this is more appropriate for superuser. – mathepic – 2010-08-22T22:23:33.680
Try http://superuser.com/ or even http://ubuntu.stackexchange.com/
– Iznogood – 2010-08-22T22:23:46.487