I've recently been reading through "The Mixing Engineer's Handbook" Second Edition by Bobby Owsinski. Although it isn't exclusively a surround sound tutorial, it does include three chapters devoted to the subject:
Chapter 12 - Surround Basics
Chapter 13 - Why Is Surround Better Than Stereo?
Chapter 14 - Data Compression Used In Surround
I've enjoyed the book so far and have incorporated some of the techniques into my own practices.