Hehehe, buy linux. There are some distros out there that actually do cost money like linspire.
I have always been faithful to DistroWatch.com. I always visit there for information regarding new releases and download mirrors. If this is your first time using Linux I recommend, like most other people will, Ubuntu. It's easy to install, configure, and run without any of the major headaches for new users like other distros.
Linux ISO is a good place which has a lot of mirrors for a lot of distributions. For screenshots, distrowatch is the place to go. I reccomend any of the following for new users: SuSE, Mandriva, Ubuntu, and if you want a small challenge with learning, but not too hard, Fedora Core. Don't pay for linux. Paid distros are no better, just that they have some non free drivers/apps and stuff, which defeats the purpose of linux, free versions are just fine for non-business use.