Following the Livna instructions for installing the driver for your kernel. If, after studying the instructions from Livna, you still have questions, return here. A quick google show that your card is supported by the n Vidia-96.43 driver.BUT (and an important BUT), do not get the driver from the n Vidia site. Your driver in rpm form (the package manager for Fedora) is there.
There used to be some advantage in terms of certain files not getting crapped on by the n Vidia install action too, not sure if that is still true.
Fedora Core 6 is the first Fedora distribution that allows you to add repositories other than the official Fedora ones at installation time (if you have read the installation notes you might have noticed something about that).
However, if you installed with only the default ones, It is easy to add repositories after installation. Go the the FAQ page and proceed from there: Lots of these packages include proprietary (binary) video (and other) drivers that Fedora will not include in their distribution (it's policy).
You can get lots of things that meet your needs from other places.
If you get packages (rpm's) from repositories like Livna, you may find that it's easer to get them installed and working than it would be if you had to find source and configure/compile on your system.