The Autism Answer Book: More Than 300 of the Top Questions Parents Ask, by William Stillman.
The ADD & ADHD Answer Book: Professional Answers to 275 of the Top Questions Parents Ask, by Susan Ashley, Ph.D.
I found both these books to be too general to be of much use. In addition, they are written from a very mainstream perspective, and ignore or only briefly mention alternative therapies and even dietary changes which have been helpful to so many people.
Disclaimer: I received complimentary review copies of these books.