Windows is still supporting games and the selection of games available on Steam for Linux, while numerous, is mostly indie games. That is, don't go jumping into Linux thinking you can play all of your games. I suppose for games that don't have official support, you could trying running it with WINE.
Also since Linux is a different beast entirely than Windows, I highly recommend reading literature on it like http://www.tecmint.com/60-commands-of-l ... nistrator/
. You'll be spending more time in the command line than you'd like.
Actually before you even install Linux on your computer as a bootable OS, go try it out in a VM like VirtualBox.
EDIT: Here's the low down on game compatibility.
I have about 310 games from mixed categories (indie, big name, old, new, etc.)
Mac OS X supports about 90 of these games, Linux supports 56 of these games. Games that seem to have support for certain are Source, Unreal, and Ego engine games. A lot of games made in 2012 and beyond seem to have it too.