I recently switched from openSuse 11.3 to Kubuntu 10.10 (Maverick) after ten years of using SuSE/openSuse. Since Kubuntu is fond of using sudo to perform admin tasks, the first order of business was to reclaim authority over root.
Note that sudo is fine for the odd task or two, but if you are going to be doing some serious admin work, doing it as root will save you from constantly having to type sudo.
The procedure is as folllows:
sudo passwd root
<new root password>
<new root password again>
You can now login to a root shell with a clean environment (`su - root'), perform your admin tasks, and then `exit' back to a normal user shell.