"How do you decide on which are the good ones?..."

We had a reasonably lengthy discussion about this book on the forum here just after it came out and people had read what it said. That way I got a good idea of the proposals it was putting forth without having to read it myself - I think it was Jon B who posted a summary with links to pics.

"why read books JUST about Giza"

Absolutely, I agree, and the book you referenced is a good one, although I would advise people to read Ancient Egypt: Anatomy of a Civilisation by Barry Kemp instead, which has much of the same content - both works are really based on the excellent work of the British Egyptologists - Petrie, Emery, Somers Clarke, Quibell etc etc.

Dave Light.