While lvlamb is correct, it's still a good idea to run X -configure and move the new configuration file to /etc/X11/xorg.conf, if anything it'll simplify making future changes. (
I like keeping it there, and until recently, I owned monitors that required specifying Vert/Horiz values.. ).
Personally, GUI's are overrated.. and no offence to the OP, but they should definitely not be displayed by default.