Basically if you were using windows server 2003.. You'd use remote desktop to access your server..
With ubuntu desktop u use basically the same thing but its called NX client.. Same proceedure you just put your server ip in root name and password.. You will get a desktop enviroment..
This is what your desktop will look like and as you can see everything is pretty easy to navigate around..
As for installing torrent clients this is very easy to do.. I believe the newest version of ubuntu desktop already has a torrent client built in. But to install utorrent you will need wine to emulate windows.. sounds pretty scary but its not at all.. If you wanted me to talk you throught the basics and help you out even if you want me to install utorrent for you than i will certainly do it for you no problem.
As for guides on ubuntu i allwayse use this website:
http://ubuntuguide.org/wiki/Ubuntu:Gutsy
Its got nearly everything you need to know about linux desktop and there really easy to follow basically copy + paste into SSH window.