There are a numerous of Distributors available out on the net for download or to buy.
Linux is a free operating system with all functionality and possibilities you can imagine there are a thousands and more programs and tools available for all various kind of distributors.

Before you download a distributor 

if you found a disto you might like (try several) download it, I suggest you download all cd's they offer so you don't get in trouble later. While it's downloading you can read the installation documentation online to get a little idea what you are about to get into.

Local Mirror