Sit down and read it on a fine day overlooking the sea and the surf and you'll go back in the water understanding so much more - It really is that good, even for such a small volume. After reading three other books on how to learn, this is the one that is making sense of all the others. That, and Wingnut's Art of Longboarding DVD if you can find it.
The section on reading the water surface to identify rip currents I haven't seen described anywhere else... plenty of books explain the dangers of rips, but not how to find spot them on the water surface
By all means buy some other step-by-step photo books, but get this one too