First things first, go to
http://www.sabayonlinux.org and download their v3.3 ISO file. A new version is due in a little while, but if you want to install the stable version, you should get this only.
Its a big download (about 3.2 GB) but it installs every application you will ever need! It comes with Beryl installed already (which has some really hi funda effects) as well as all your other major applications.
And it has a reputation as being a hard distribution to use...but I'm a total newbie. Like you I am very new to the whole thing, and I only shifted less than a month ago. I started off with a distribution called PCLOS but I got sick of lack of inability to install third party software as well as bad repository, so I tried out Ubuntu, Linux Mint, SuSE etc and finally settled on Sabayon.
This is the prettiest and simplest distribution out there and it WILL run MP3s, all your office documents, pretty much every multimedia file out there...so give it a go. If you have any trouble, drop by the Sabayon forums, where there are a lot of people will to help you out. If any trouble, there is also the Sabayon Wiki and other community docs that can help you out.
I HIGHLY RECOMMEND SABAYON!
PS: What's your HDD capacity? You didnt mention...Sabayon need 10 GB to install fully...but thats because it install almost EVERY application out there you could ever need...so the system works great out of the box!