After spending a seemingly interminable time with the camera manual and a great Nikon tech, attempting to get my D90's CLS and my SB 600 to play well together,and finally succeeding, today I received my copy of Darrell Young's "Mastering the Nikon D90. Beautifully printed, Color illustrations!
Right there on page 299,understandably written, is the answer it took us the better part of an hour to figure out!
If this is any example of the rest of the book, I shoulda bought it before I got my D90! Definitely a step or three above the factory and 3 other manuals I have read, trying to understand my camera. Can his other manuals be less helpful? I doubt it!