The supplies you are going to need is one flat shovle to form the ramps and at least one spade shovle(pointy),some good friends to do most of the work and tell them to get there own sovles, dirt if thats not obvious,and a weed whip if possible.

For the building part is the hardest part this is where those friends come in handy. The only jump i am going to talkabout is the double. The double is basicly two ramps one for take off and one for the landing.
First decide how big you want your ramps for begginers i reccomend a 1 to 3 foot tall ramp with a 2 to 6 foot gap. Once you have your mounds of dirt where tou want them compress them i have my fat friend walk on mine keep doing this till you have 2 compacted mounds of dirt then with the flat shovle carve out the shape of the take off and the shape of the landing. The landing shound be twice the size of the take off and should also be slanted. The take off should round up like a spoon. Make sure the the ramps are very compacted you may want to get them wet that helps alot otherwize that happens when it rains. Then your good to go now start makeing ramps.