Well I just started it, I am reading it in my spare time. It goes into a lot of detail about the aspects of a helo though (at least as far as an aviation newbie like me could be concerned). It goes into a lot about how lift is generated from the rotors, the engine, the tranny, types of helos, instruments, a lot about rotors themselves, etc....it also gets into the mathematics and physics somewhat in one section on helo mechanics, but it isn't an engineering text where you need a year of calculus or something to understand it.
It goes into detail about the tail rotor too, like how and when a helo can fly without a tail rotor, why tail rotors are placed in different areas of the tail (like some tail rotors are placed at the top of the "tail fin," some at the bottom of it), etc....it seems to give the reader a very thorough grounding in all the aspects of helos.
It also has a lot of diagrams throughout for all the different subjects, which helps clear things up.
I am not a pilot yet, so I mean my critique of it is limited, but it seems like a very good text for people wanting to learn about helos.
This is just a sidenote in case anyone is interested, I also saw in the same library a book on visual heads-up displays for helicopters (like 200 or so pages all on HUDs in helos). I forget the title though, or when the book was published, I can check though.