This just contains similar information to the Nikon D800 manual, except it is in larger print. The guide is therefore relatively big (A5 size). The ring binding is odd.
I have flipped through this guide briefly and I don't think I'll be looking at it again. I can't see why anyone would bother taking it with them when they go out shooting photos - you will know all the simple things already.
I have just got the full David Busch's full guide to D800/D800E. I hope that this has more useful info.