When someone is switching from windows to Linux the first distro I recommend is Linux Mint. Mint feels similar enough to Win7 that any windows user can drop in and learn it in no time, my, tech illiterate, 76 year old mother has been trying a Mint live USB and has needed very little help.

I say start with Mint and get to know Linux, then if you want to try other distros you can, but at least you'll have a solid foundation to jump off from.

What ever you choose, welcome to Linux!