startx but that will only work if you have your Xserver configured properly.
To configure your Xserver, either Xorg or XFree86, use on of the following(listed from favorite to least):
nano /etc/X11/xorg.conf (pico or vi would also work)
ALl of those also work replacing Xorg with XF86 if that is your choice of Xservers.
Things you need to know before you start:
1)The horizontal and vertial frequency of your monitor.
2)What driver your video card uses. Oh i just saw you use nvidia drivers. I guess you want 3D acceleration for them. That is a whole different topic....
3)The keyboard, mouse, and other sections should be pretty self explanitory.