With the BootCamp Assistant 3.0 (and OSX 10.6 Snow Leopard) the Driver Download never worked except for MacBook Airs.
The Boot Driver version 3.0 are located on your OSX Snow Leopard Install DVD.
Boot into Windoes and insert that DVD. Usually the Driver Setup starts automatically.
After that you can use the downloaded Driver Packages 3.1 and 3.2 and install them while in Windows (these are .exe files - only executable in Windows).
Hope it helps
And if you don't have the disc, like me, and millions of others?
Use saturnotaku's link for the drivers and call Apple and order a replacement for the missing disk (you may need it in future so get it while you can)