Ubuntu is just about the worst Linux distro. available these days. Canonical who produce Ubuntu have become arrogant and ignored users needs however well voiced across the many Forums that make reference to Ubuntu. For example Ubuntu 11.10 doesn't offer the classic GNOME Desktop and it doesn't include the Synaptic Package Manager despite the fact many users did not want these changes. I used to have much time for Ubuntu starting with Ubuntu 6.10 finishing with the last decent release which was Ubuntu 10.04 LTS
Overall a Linux based platform can perform most of the tasks equally as well as a proprietary platform using OSS. Linux does have its limitations with some applications and in particular gaming.
I suggest continue working with XP and setting up a Dual Boot with Linux. I thoroughly recommend Linux Mint 11. Its easy to install and easy to use plus it comes with much of the software you are likely to need preinstalled
Linux Mint 11 Download
http://www.linuxmint.com/edition.php?id=81
How to dual boot Windows XP and Linux (XP installed first)
http://apcmag.com/how_to_dual_boot_windows_xp_and_linux_xp_installed_first.htm
Linux Mint 11 Release Notes/User Guide
http://linuxmint.com/rel_katya.php
You download the ISO. image of any of Linux Mint 11 then you need to create a Bootable LiveDVD
https://help.ubuntu.com/community/BurningIsoHowto
Linux Mint 11 can also be run straight from the LiveDVD from Boot without touching your Hard Drive
LUg.