Youve got a couple of choices. During the Mandrake install, you can tell it to install kernel-source (or just check the "development packages"; that should do it too), and then you'll be able to use the .tar.gz version of both the kernel and GLX.
Advantages: If you ever upgrade your kernel (and have the new kernel source available), you can recompile the same nVidia kernel and reinstall it, and it'll work.
Disadvantage: If you don't have the kernel source available, you can't use it. It's probably also a little harder to do it this way.
The other way is, post-installation, you can download and run the NVchooser.sh file that's referenced off the driver page, and it will tell you which files to download and install.
Advantage: it's probably a lot easier.
Disadvantage: If you ever change out your kernel, these drivers that you download will not
work. Don't even bother trying them.
I'd go with the .tar.gz's, personally, but that's just me.
Oh, wait a minute, never mind. This is Mandrake 9 Beta, so there aren't any kernel RPM's on the download page that you can even use. You'll have to go with the SRPM's or the .tar.gz's, and make sure
that kernel-source gets installed when you install Mandrake (for either one of them). You'll also need gcc and make, but as long as kernel-source is selected, these should be too.
Hope this helps. If you have any questions, read the README (it's got more info in it than anyone should ever know
), and then post them if you still can't find the answer.