Not a book or manual specifically but just read an article that touches on this and implies that early intervention with AD children can mitigate the course to some extent. Gives an overview of the treatment, albeit briefly. I'm sure there are probably some good citations to follow up on within the article as well.
Dawson, G. (2008). Early behavioral intervention, brain plasticity, and prevention of autism spectrum disorder. Development and Psychopathology, 20, 775-803.