Just a bit of slightly bias advice:
- Stay away from RPM distro's (Suse, Red Hat, Fedora), installing software can be a pain with all the dependencies.
- You Probably want to use KDE as your Window Manager. It is much more user friendly for someone switching from windows.
For these reasons I am going to suggest Kubuntu
as the best linux distro for you. The main CD starts up as a live cd (lets you run the OS without touching your HD) and then install it if you like it.
Also, why do you want to use Linux? It sounds like it is to get away from windows (the most popular reason). In this case you might want to try PC-BSD
. BSD is another flavor of unix and is somewhat similar to Linux. PC-BSD is really user friendly, but powerfull and secure at the same time.
You will probably also want to run windows at the same time, Right?
If you do I would recommend you do it like this:
Save all your data to a removeable device (DVD, External Hard Drive, etc.)
Use a live cd (Kubuntu will do find) and format your hard drive (erasing all data along with windows).
then Re-install windows, but this time only use about half of your Hard drive.
Then you can re-install linux on the remaining space.
It is possable to shrink a Windows partition, but it is not wise as it often ends up in lost data.
Good Luck and Welcome to Linux & LinuxQuestions!