Bryan Peterson, People In Focus, How to photograph anyone, anywhere.  (***)  A comprehensive guide to the art of photographing people, including everything from how to choose potential subjects, how to approach them and get their permission, how to compose the shot, and what works and what doesn't.

The Portrait, Kodak Books, Professional Techniques and Practices in Portrait Photography.   (**+)  Even though it talks about "professional techniques", the book is a better fit for the advanced amateur, but it is a good general guide to methods and guidelines for taking portraits.  Most of the book deals with candid portraits, but there are sections on wedding photography, fashion photography, boudoir photography and how to present your photographs to the client and for sale.