Here this site goes over most of the pros and cons for switching over to Linux
http://www.whylinuxisbetter.net/
The main problem is if you feel like you need to use programs that only run on Windows. If you feel like this at lest try the Linux alternative before you give up on Linux. Like try Open Office before you say you can't give up MS Office. Open Office does most of the same things that MS does and it does something better. However there is no grammar check.
PS a few Linux distribution you should look at are:
Ubuntu
http://www.ubuntu.com/ (has the best forums)
Linux Mint
http://www.linuxmint.com/ (mint is made from Ubuntu but is a little more ready to use after you install it because it comes with flash and dvd play back)
Opensuse
http://www.opensuse.org/ (there is a lot of anti Opensuse now because they have been working with Microsoft)
PCLinuxOS
http://www.pclinuxos.com/ (said to be easy to use but I really had problem with it couldn't even install it)
Maybe Fedora
http://fedoraproject.org/ (but it has a lot of draw backs like not being able to play mp3s)
Stay away from distribution like Slackware, Gentoo, and Sabayon at lest at first I'm not saying there bad but there not for someone new to Linux.
Distowatch has information about a few hundred different Linux, Unix, and BSD distribution
http://distrowatch.com/
You might also want to check out and join the Ubuntu Forums
http://ubuntuforums.org/ so you can ask question there it really has some great members who are both nice and helpful.