Get Driven to Distraction today. It has been out for quite a while but is one of the best introductions you'll find about ADHD. It is written by two doctors (one who has ADHD) that are very active in the field. There is a general explanation of ADHD, both adult and child: what it is, how it affects you and others, medications and many life stories that may have you crying as you see yourself in their stories.

Please be aware of the " I'm going to get to that" syndrome we with ADHD fall into and go right out and grab it.