Some good advice from previous posts.
IMO the Carl Lopez "Going Faster" book is the must have. Because of the tie-in with the Skip Barber School the book mirrors the teaching-learning experience of the school programs -- starting with the basics of finding the correct line and working your way through braking, accelerating, rotation, passing, etc. Also, rather than being one driver's opinion on how to drive around a closed course, in "Going Faster" you are getting the collective wisdom of many drivers and instructors, presented in a organized approach -- developed over a 30 yr period -- that is designed to teach. If you find yourself at a Barber School in the future (highly recommended) you will truly appreciate both the quality of the book, as well as the fantastic learning experience of the Barber program.
Alan Johnson "Driving in Competition" is the perfect primer. Carroll Smith "Drive to Win" is a little more oriented towards a driver on a pro career path as I recollect, but great reading. The Paul Frere "Sports Car and Competition Driving" is a classic, as Jenks "The Racing Driver" (I'm re-reading this right now). You can draw good stuff from just about any of the books out there, but the Lopez book is the one to have.
Good luck, Mike