Install XBMC on existing Ubuntu 12.10 Server

Hi all I have a HP Micro server on which I have installed:

Ubuntu 12.10 Server
Couchpotato
Sickbeard

What I want to do is install XBMC so that it starts automatically but I still have access to the other apps thru the browser and also can still use putty to connect.

I have an NVIDIA GF610 installed.

Is there a tutorial to follow ?
I am a bit lost here as I am not if I install XBMC-standalone or not.
How do I get XBMC to run on startup but still have access to all my other apps via browser and putty.

Thanks guys.