Welcome to LQ!
What do you want to know? Most of us here will be glad to help.
I would start out with a nice, easy distribution of Linux such as Ubuntu. You can get it from www.ubuntu.com
Some Windows games can be played using emulator programs. Having said that, in my experience it is best to create a dual-boot system where you can choose either Windows or Linux when you turn your computer on. This way, you can use Linux for everything except games, and Windows for games.