Take a look through these. There are more but these are what I found in about 5 minutes. Hope it helps
Step 1. Take the above dudes advice about avys.
Step 2. Look for suitable drop in plus landing areas for the type of jump you want to build (step down, step over, hip or natural table)
Step 3. To make you jump its best to cut big blocks of snow out. Pile them in to the general shape you want, and over build it a bit then pack it down.
Step 4. While you like the snow from your jump settle and set, prepare your in run, sometimes you'll have to dig it out of the side hill a bit or take out some bumps. If your digging into a side hill, a good tip would be to imagine your in run and try to only dig half of it out of the side of the hill while building the other half with the excavated snow.
Step 5. After your generally shape jump is packed and settled, finish carving it, how much angle you put on it depends on the kind of jump, the distance to the landing and the length of the transition of the jump. A good tip is to carve out the middle one shovel width get it close to where you like in the bring the rest down to match.
Step 6. You may have to let it set a bit longer depending on the snow and temp, but generally speed check and hit!