On insurance-
I checked my coverage with Mercury and their policy is clear... If you are taking part in a Performance driving School or Driver Education with no timing involved, even on a racetrack, you and your car are covered. If you are in a timed event like Autocross or Time Trials it is competitive and considered racing... You are not covered. Other insurance carriers may vary greatly from this. Our local track days include PCA liability insurance which covers injuries. You are responsible for damage to the facility, your car, or damage to someone else's car.
On Performance Driving Schools-
The Porsche Driving Experience, Bob Bondurant, and Skip Barber all have great programs with professional instructors but they are very expensive at $3000 per weekend. Both the POC and PCA have local programs based on the same curriculum as the others for $200-$300. Check your local clubs. One of the great benefits of owning a Porsche is having access to some of the best driving instruction available at a fraction of the cost of Barber or Bondurant. Don't miss this opportunity. Here is one example. There are many others.
http://www.pcasdr.org/img/2008/Calendar/DSchool/School%20Ad-%20Spring%2008.pdf