Here is a guide to install XBMC using the Team XBMC PPA. Before installing XBMC make sure you have the latest drivers for your video card installed installed on your system.
To add the PPA and install XBMC open a terminal window (press Ctrl+Alt+T) and copy+paste the following lines:
sudo add-apt-repository ppa:team-xbmc/ppa
sudo apt-get update
sudo apt-get install xbmc
When XBMC is installed you can close the terminal window and to start XBMC press the SuperKey and type: xbmc.
XBMC is an award-winning free and open source (GPL) software media player and entertainment hub for digital media. XBMC is available for Linux, OSX, and Windows. Created in 2003 by a group of like minded programmers, XBMC is a non-profit project run and developed by volunteers located around the world. More than 50 software developers have contributed to XBMC, and 100-plus translators have worked to expand its reach, making it available in more than 30 languages.
XBMC Homepage.