I've been having to run Redhat 9 in 800x600 because I didn't have the driver. Now, I downloaded the driver, and set the screen to the correct type (generic laptop screen capable of 1600x1200, which I was told was the correct setting for my computer, as my particular screen isn't one of the available options) now, when I start the xwindows client, it just goes to a black screen. I've noticed that on the command line it says something about the driver not being available, but I installed it, so I'm not sure what it means. I installed it, it said the install was successful, and in display configuration it says that the nv driver is selected, and the driver I installed isn't on the list, so I'd assumed it just updated the one I already had. Now I realise that it really didn't so... is there something I can do? Either change the settings, or correctly install the driver?

This might not help, but if you've installed the NVidia drivers, you'll have to change the "nv" to "nvidia" in your XFConfig file. If you haven't changed that yet, you'll need to. I think it mentions this in the FAQ for the drivers, but I don't have the FAQ handy right now.

hrm... I can edit the file from the command line using vi, but how do I save and exit? I mean, I found an explanation on the net, but it just says to type ZZ- how do I make this a command, rather than just typing it? (ie: it thinks I'm just writing, rather than telling it to save/exit)

In vi and its clones you press "esc" to return to command mode from insert mode. You can then execute commands.
My preferred method of writing the file and quitting the editor is to use :wq
the colon (:) preceeds commands.

thanks. I ended up going on IRC and talking to people, they helped me figure out how to use emacs to do it. Thanks guys, for the help- now my screen actually works! This is a source of great joy.