You've just download the latest and greatest version of Ubuntu Linux and it didn't cost you a thing. You breezed through the installation and a brand new desktop is staring you in the face -- now what?
There are a few things you'll need to do if you want to get the most out of your Linux desktop. But don't worry, none of this is too complicated. In fact, it's much easier than trying to do the same on Windows or a Mac.
Optimize A Fresh Ubuntu Installation - Wired How-To Wiki