ahah, it's a real newbie
PLEASE READ this 20 times before trying it out!!!!!!!!! I'm NOT JOKING!!!
logging in as root is quite simple, but you have to learn how to use a konsole...
open up a konsole
and with 'su' you can log in as root
but when you have to install the nvidia drivers a konsole won't do you any good.
you have to go to text mode (which is done by pressing CTRL-ALT-F1 (2,3,4,5,6) pressing CTRL-ALT-F7 will put you back to graphical mode..
go to text mode
try loggin in as root and familiarize yourself with 'vi', its an editor.
remember if you don't know how or what, try 'man <command>' which gives you info about the command. and you'll need it.
now when in vi, you can't just edit a file, first press INS to edit a file and when done press ESC then you can do this: ':wq' which Writes and Quits, got it?
now go to text mode, log in as root, kill the X-server ( execute command 'telinit 3' ), install the already downloaded nvidiadriver by 'sh NVIDIA......' )
and when done edit the config file ('vi /etc/X11/XF86Config-4') edit nv to vnidia and comment out dri, glcore, and add 'load "glx" ' to it. save and start graphical mode again (init 5).
now which distro you said you were using???
Alien is my name and headbiting is my game.