I am looking to create a simple offroad type racing game. I am not concerned with actual racing physics(turning, transfer of weight, etc.) at this time but just in making the vehicle stay on the ground and jump over hills. For instance, say the vehicle is going down hill,it reaches the bottom, and then starts going up another hill. When it reaches the top of the hill it is going fast enough that it jumps and lands farther down the hill. I am not a physics expert and have not found any tutorials that would explain this. The best i have found on gravity is a simple tutorial that is in 2d and just involves the player pressing a jump button. Any help or pointers to good tutorials is appreciated.

grhodes_at_work posted some nice links for physic
here.