Strap on the seat belt and take some valium! (Just kidding--a stiff couple of drinks should be enough!)
I started teaching my son to drive on his 15th birthday. I took him to a big, empty parking lot and started him out on simple maneuvers like starting the car, putting it into gear, moving forward, braking, staying w/in the lines, etc., slowly graduating to turns, reversing, etc. Then, I got him professional driving lessons--lots of time behind the wheel is the key to safety and success. Most insurance companies give you a discount if your child takes on-the-road professional lessons (and it can be less nerve-racking for you). Also, they will give you a discount for your son being a good student. This can save you several hundred dollars each year, and is good incentive for your son to maintain good grades. We told our son that his driving privileges would be revoked if he couldn't get the discount.
Something else to keep in mind -- most driver education courses require class instruction. Many companies will allow your son to complete this online, sometimes at a lesser cost. It's easier for you, since you don't have to drive him anywhere, and it can be easier for him since he can take the course as his schedule allows (some teens are so busy!). BTW, the on-the-road part of the class could not begin until the class time requirement was fulfilled.
It was really important for us that our son be able to get his license when he turned 16, which he did on his first attempt. My husband had to spend that year studying out of the country and I was going to be staying with him for the first month right after our son got his license. Our son, however, was staying home with relatives so as not to miss school and he needed to be able to provide his own transportation. Later in that year, it was very helpful to have him driving to help with picking up our younger daughter and running an occasional errand. It also gave him much greater freedom. Fortunately, we trusted our son's judgment and sense of responsibility -- he's always been a very analytical and careful kid. He did get one speeding ticket, though, at a speed trap. We could have fought it but HE even felt that he deserved the ticket, the fine and the sentence (restricted license for one month, which was difficult for everyone!) -- now, at 18, he tells me to slow down and be more careful! ;-)
BTW, do be ready for minor fender benders during the learning process and handle them calmly. My son took a slow right turn too close to a gate post and smashed in the passenger side door within a few weeks of getting his permit. He felt terrible and swore that he was never going to drive again. I told him I was upset about the door, but that I'd done the same thing myself (he was driving my big fat minivan at the time) and then made him drive with me for the rest of our errands so he could regain his confidence. Yes, I was pretty shaken up, too, but I didn't want him to know that!