Apple has posted the feature guide for the soon-to-start-shipping iPod Touch. A nice 85-page PDF document that will answer just about any question you have regarding the Touch. It covers everything from the Basics to Music and Video, Photos, the Wi-Fi Music Store, Applications and Settings.
It would have been nice to include a Notes application similar to the iPhone but overall the only real disappointment on the Touch is the lack of the ability to edit or create events on the Calendar. Of course both of my complaints seem a little silly considering the Touch is really an iPod and not a PDA.