usually the drivers for tablets should show up in the system preferences, is it an issue where the drivers are not recognizing the tablet, but they installed okay? or is it something where not even the drivers install properly?
Another thing to double check, especially if you're new to OS X, is that there are often times drivers or programs that are made for 10.4 and up and then a newer version for 10.5 and up. Do make sure you've got the 10.5 drivers over anything that might be potentially older.
Hardware: White Intel iMac 24in, 2.66 Ghz Core 2 Duo, 2 GB ram. White Intel Macbook, 2.13 Ghz Core 2 Duo, 2 Gb Ram. Cintiq 12wx.
Software: CS4 Master Collection, Final Cut Studio 2, Cinema 4d, and a few other scatterling programs of various shapes and widths