My older two have their licenses; the third will start drivers ed this spring. As with everything else with the boys, I just took it a day at a time. I had expected to be a nervous wreck, but really it has not been that bad!
On the plus side - I don't have to drive them everywhere! We also have the boys pay for their own insurance and gas; I think this makes them take more ownership in what they are doing in the car (and at school, too because good grades mean better insurance rates!)