If you are lucky enough to already own the EOS-1D X, Canon recently posted 18 on-camera tutorials for download and playback on the camera's back LCD.

The on-camera movies encompass everything you need to know to get up and running with your new SLR.
To playback follow these instructions.

These on-camera tutorials are also available for the Canon 1D Mark IV, 5D Mark II, 5D Mark III, 7D and 60D.