I'm not gonna be much help because I don't know if there are any peculiarities with setting up X for a laptop, not having done this, but you could try this.
Log into a console in text mode as root.
Try xf86config
mv XF86Config XF86Config.old
or something like that first so you have a backup.
This will go through some questions re: your keyboard, mouse, screen etc. and set up a basic XF86Config file for you. Make sure you have details of hardware to hand, e.g. refresh rates and resolutions before you start.