I just starting using Ubuntu, 12.10, and would like some detailed guides for doing such things like install GPU drivers, installing custom desktops, etc.. I am a programming noob, so please making them detailed but not where I have to look up every fourth word. That will not help much.
There is official documentation:
https://help.ubuntu.com/12.10/ubuntu-help/index.html
Community documentation
https://help.ubuntu.com/community
Also the Ubuntu Forums
http://ubuntuforums.org/
And, if all else fails
https://www.google.com/
You don't need guids for that.
Regarding the GPU: Ubuntu ships with the OS driver by default, which means poor performance but they work, sometimes even more stable than the proprietary ones. If you want the full performance you have to install the proprietary driver from AMD or Nvidia by going to system settings, software sources, additional drivers and activate them.
You can select a theme in system settings, too. To install a theme just copy the folder to ~/.themes
Installing other desktop environments can be done like installing any other application. Just go to the software center and search for it.
The links above look sane, so use them and search for yourself.