I thoroughly recommend Linux Mint 9 LTS which is built upon Ubuntu 10.04 LTS. Its easy to install and easy to use plus it comes with much of the software you are likely to need preinstalled
Linux Mint 9 LTS Download
http://www.linuxmint.com/edition.php?id=52
Linux Mint Installation Guide
http://www.linuxbsdos.com/2009/12/03/linux-mint-8-installation-guide/
Linux Mint 9 LTS Release Notes/User Guide
http://www.linuxmint.com/rel_isadora.php
You download the ISO. image of Linux Mint 9 LTS then you need to create a Bootable LiveCD for installation
https://help.ubuntu.com/community/BurningIsoHowto
Linux Mint 9 LTS can also be run straight from the LiveCD from Boot without touching your Hard Drive
Once installed I suggest upgrading from the default Firefox 3.6 to Firefox 5
How To upgrade to Firefox 5 on Linux Mint 9 LTS using the Mozilla Stable PPA
http://www.webupd8.org/2011/06/firefox-5-lands-in-firefox-stable-ppa.html
LUg.