All of the books mentioned are excellent. They are the ones I recommend to customers the most. Unfortunately with reef books most of the best ones are very expensive.
For people who do not have that kind of money to put out on a book, I usually recommend a book that is published by Barron's. It is called Corals and is actually written by John Tullock. It is almost a shorter less detailed version of his larger more expensive book. It is very up to date (even mentions deep sand beds) which most of the other pocketbook type of reef books are not. And it is only about $10.
It is a good starter book for a person who is new to the hobby or just looking into getting into it and has a limited budget.