Where do I get Linux?
Do us all a favor and use SuSE 10. It's stable, there is a commercial version, it has excellent hardware support, there's no good reason to not use it. The home page for the community (read free) version is here:
http://en.opensuse.org/Welcome_to_openSUSE.org
You want version 10. The download links are here:
http://en.opensuse.org/Released_Version
I have SuSE installed, now what?
Here's a GREAT intro guide for Windows users. It will even help you get DVDs playing.
http://spinink.net/suse-for-windows-users/
Here is another link that will help you get more up-to-date software and some packages that SuSE can't legally provide:
http://susewiki.apanela.com/goodlinks:yast_sources