I just skimmed through this and thought id add in.
Building a laptop is completly different from building a PC. The IDE cords are like ribbon, and everything is much more delicate and has to be in place strategically, unlike a desktop tower where you can litterally throw everything together. (sorry if this has already been mentioned, im lazy)
Im about to go off to college (Georgia tech, and computer engineering, so our interests are atleast related...somewhat) and I just ordered a Dell Inspiron 6400, which sounds like what you are getting.
But a couple of suggestions. I would definately upgrade to the 1.83 ghz, and atleast. The graphics card is great, the one I put in my order is only a 256, but hopefully enough to run all the games and whatnot that I want
and one last thing, the hard drive. 80 gigs should be good. any extra I would suggest an external usb hard drive, which can be expensive, so if you want to be cheap like me, buy a normal computer hard drive, and put it into a 20$ hard drive enclosure.