as stated by others, just get a general understanding for shutter speed, ISO, and aperture. Then you want to learn about composition. Rule of thirds is your best friend.
I've taken classes in my high school and college, but I've really learned more by teaching myself and watching videos or reading photo blogs. Just experiment with different settings/techniques until you feel confident.
Like someone said, have someone jumping. But have the camera at a low angle with a wide angle lens to give it that illusion. With this, you don't even need photoshop.