Jeff Gilbert said:Jumping can get quite involved, not sure if anyone can safely tell you how to do it. I assume when you say you are jumping 5 feet now that you are referring to distance??
All I can tell you (that I can think of at the moment) is to make sure you are in an attack position as you launch and it helps to land on the gas so the suspension will absorb the landing. Take it in small incremements untill you know how you and your bike will react and understand body positions and techniques to correct attitude for landing. A lot of what determines jumping is the type of face the jump has on it as well the speed and attack you hit the jump. If the jump is so short that both wheels won't fit on it I'd move to a safer jump before you are kicked over the bars. The best type of jump is a tabletop with a fair amount of face, probably 15 -20 feet, the angle of the face shouldn't be too steep. If you can find one with a gradual landing, that'll make it that much safer. I was fortunant enough to practice on one like I mentioned that was about 55-60 feet accross and it came up way short a bunch when I 1st started.
How you attack a jump can make a lot of difference. If you've ever seen AX/SX, a lot of those really big jumps are hit in 2nd gear, some of them in 1st gear, going fast isn't always the key, it's how quick you are going. Make sense?
Good luck