I can't tell you how to use the mandrakeclub nvidia rpms, but all I had to do was this:
Install the relevant kernel. Get the kernel source.
Install NVIDIA's driver (from www.nvidia.com
follow the instructions in the readme - mainly:
go to a text console
login as root
init 3 (stop the GUI)
init 5 (start the GUI)
Each time you change kernel, you'll need to re-run this.
It may be worth printing the readme before you start.
Save your old XF86Config-4 (and your new one - if you run the mandrake X config tool again, you'll overwrite it.
I did this on a P4 - it should be fine on an AMD - but I have no actual knowledge.
Remember, when you add a kernel using urpmi, it will end up as an option in /etc/lilo.conf, but you'll have to run lilo to get it to appear in the boot menu. If you want it to be default, edit /etc/lilo.conf