I've been to driving school twice now (yeah, apparently once wasn't enough for me
). First time I went was before I got my Camaro on the road. I'd never been out on a track before. Over the course of several days, I learned how to drive Corvettes reasonably fast. When I jumped in my Camaro though, all of my new found driving skills got me right into last place at my first event. From there I had to start learning how to tune, and feel my car out. Most driving school classes aren't going to let you play around with out traction and stability control on, and it makes finding the limits of the school's cars a bit more difficult. It is really easy to over drive them without being able to tell when the computer is saving your ass. The reason I went back recently was because I felt like all of the seat time I'd gotten at events had allowed me to be able interpret what my car was actually doing. I'd gotten better at judging corner entry speed, weight transfer, etc. I could kind of tell when I was pushing the limits of traction in my car. So, the second time I went out to Bondurant, I could put all of the instructor's advice into context. Sure, I did everything they told me to do the first time around, but I wasn't necessarily able to tell if I was doing it right. The second time around, if the instructor told me to lift and turn, I could do it with way more finesse than several years before.
Greg is right about Bondurant, the instructors are a wealth of knowledge, not to mention patient. Since you've had experience with fast stuff in the past, I'd recommend getting your car out to an empty parking lot, and/or and autocross, and getting to know it a little bit first. Once you shake off some of the cobwebs, then head out to Bondurant, where you will learn how to react to what you are feeling in the car, and then how to tie all of the individual components of driving together.
Matt