Hi
Under the "Factory" there are 12 sections and under "Garageband" there are quite a few individual sounds.
If you installed the entire content of the Logic 8 disc's this is what you should be getting.
Remember though there are more instruments and settings available through the Channel Strip Settings menu. The benefit is that these instruments come loaded with effect plug-ins too. The downside is that you won't often know which of Logic's instruments they pertain to (EXS24, EVD6, Sculpture etc)...
At the bottom of this menu are all the Jam Pack Instruments too.
In addition, another tip to get access to more preset sounds is to:
1. search through green apples in the Loop browser.
2. Drag one you like onto an empty instrument track. 3. Delete the MIDI region if you don't need it and
4. save the Channel strip setting so you can access it later.
Cheers
Rounik