How-to:
Here are a few great clips to get you started from Bikeskills.com
Pumping For Speed and Control
Being able to pump the trails and dirt jumps is a key skill necessary to have dialed in order to take it to the next level.
How to jump a mountain bike
Drops: Here is an good clip from the guys at Fluidride and Decline Magazine.
Jump technique: Learn the difference between racer style and popping a lip, and get more control