Ask your therapist or members of your Narcotics Anonymous group what books they recommend. Unlike regular self-help books, drug addiction and recovery books deal with physical and emotional issues, so it is best to ask someone who is familiar with all aspects of drug addiction for a recommendation.
Search drug addiction and recovery websites and see what books they suggest. Some of the books are reviewed by doctors or other professionals who contribute to the site. This will give you a clear description of the content.
Browse the recovery section of large chain bookstores in your area. Borders, Barnes & Noble and all well-stocked bookstores have recovery and addiction sections within their self-help aisle.
Recall various recovery and addiction speakers you've heard, either in your recovery program or on TV. Do a Google search to see if they have published a book you'd like to buy.
Spend some time on Amazon.com and other book websites. Their search functions enable you to look for keywords, author names and publication dates. This is the best source if you want to search through a lot of books before making a decision to buy a drug addiction recovery book.