That's a pic of me on a small jump this past weekend.
Now for tips... I'm not sure where you ride and what kind of jumps you wish to do, but I'm a duner myself. So, when finding a jump at the sand dunes I would advise the following...
When you first find a possible jump, go over it slowly in second gear, get hardly any air or even roll over it. This will give you the feel of the lip, if it will launch you out, up high, and/or crooked. Then you work up your speed. When come up to the jump have a steady speed. When you get to the base of the jump, accelerate to a faster speed at which you're comfortable jumping at. If you feel you want more speed as you get closer to the lip, then accelerate a little more. When jumping, have a steady throttle going off the lip. In the air if your nose is diving give it some gas. If your nose is real high (lime a wheelie in the air) then tap the break. This will even you pit in the air. For landing. You want to start giving your quad some gas right before you land and hold it steady through the landing. By giving it gas for the landing it will make it smooth instead of bouncing you around like a rag doll (trust me, the latter is no fun).
Practice makes perfect!! Just take it slow and definitely want to be comfortable with how the lip launches you before you try going big on the jump. Hope this helps!