Windows 8 is very touch-centric, but which gestures are actually supported? This handy graphic summarises the main new options for Windows 8 on a tablet or touch screen.
Some of these options will seem obvious (moving the mouse with a cursor), and some will seem familiar from touchscreen phones (pinch to zoom). Others will require definite adjustment (swiping from the right to go back to the last app). As with any set of shortcuts, there's always a degree of arbitrariness, but learning them will save you time in the long run.
Collaborating to deliver Windows RT PCs [Building Windows 8]