There are quite a few good books, but my experience has been that I
have benefited much more from an instructor led course.
You get much faster feedback to your questions, and in ADT there will
be quite few.
The concepts are a little easier to understand if you watch someone
actually demonstrate them, versus using a book where you are trying to
do your own demonstration.
The courses I have taken for ADT and Revit have made me much more
productive than I could have been trying to learn them from a book.
The books, and I have quite a few, are a great resource after the
training.