Beware arm chair racers...learn for yourself...
I highly recommend
http://www.skipbarber.com for their courses - not cheap, but you get what you pay for...a while back I did a driving course at Lime Rock - I've never been so fast so smoothly as I did with one of the instructors there...
Just think of the 'cup of water' training example - it teaches you to be progressive in all things. Skip Barber use something similar.
Then of course there's the skid pad exercises which are fantastic if you want to learn how to control the car properly when the tail is out
