nvidia kernel and lib install
the kernel drivers are available off the nvidia site. Be careful to match with your version of linux and your own card.
Their wizzard walks you through the selection, though, as you can see, it seems inconsistant to me.
once downloaded you should log in as root and without X. There are various ways to achieve this, but the end result is that you must navigate to where you downloaded the kernel from the command prompt. Obviously there can be complications to this if you have no graphics to begin with (as I didn't). In my case I used the dual boot of this machine to burn the drivers onto a cd which I then accessed from the command line.
Instruction on the web site and in the install instructions give the correct form for calling the run script. You will find that the file name in the install file is different to that you have downloaded, be sure to note that actual name. There are other issues such as if X fails to start it will enter a routine where it tries to automatically fix itself. If you know it will fail this due to incorrect or absent drivers it is better to cancel out of this. In worse cases you may be confronted with a blank screen (I was.) I found I had to reboot (with the reset button) and cancel out of that routine as above.
Having got to this point with luck the install script throws up a basic graphics screen.
Read the doco for exact sequence of questions. You need to get to the point where you can decide if you want to compile in the headers (presumably) or download precompiled versions suitable for your kernel.
The script asks various questions as it proceeeds. You will probably want it to compile in the headers to your distro, but that choice is not straight forward as there must be compatability between the version of gcc (I think) the kernel was compiled with and the one your system has (that was used top compile your kernel. If I remember 2.3.x is is OK, read the doco.)
With that done the rest should be plain sailing.
You should be able to start X by typing X at the command line. However, really you should reboot so that your graphics front end can load properly.
There are no doubt other commands that can be issued at the command line that would hhelp with all of this, but this is as far as I know. I do know that instead of getting into trouble with blank screens as mentioned it is possible to edit one of the startup conf files. I decided not to do it that way though.