Apple includes multitouch gesture support for the built-in trackpads on its MacBook Pro and MacBook Air lineup, as well as the Magic Trackpad. With the long list of gestures OS X supports, it can be hard to figure them out. That is, until you know that Apple hid away a nice set of gesture tutorials in the System Preferences app.
System Preferences includes videos showing how to use multitouch gestures
To check out your Mac's built-in gestures, just go to the Apple menu and choose System Preferences. Now click Trackpad. Each of the options under the Point & Click, Scroll & Zoom, and More Gestures tabs includes a short video demonstrating each gesture. You can also disable any gestures you don't want to use from here, too.
This is the first place I send new Mac owners when they're ready to start learning system-wide gestures, and it's handy as a refresher when you forget how many fingers to use when swiping to show Mission Control (it's three).