Many of my clients have found the following books helpful.
Overcoming Unwanted Intrusive Thoughts
A CBT-Based Guide to Getting Over Frightening, Obsessive, or Disturbing Thoughts
by Sally M. Winston
Overcoming Harm OCD
Mindfulness and CBT Tools for Coping with Unwanted Violent Thoughts
by Jon Hershfield
The Mindfulness Workbook for OCD
A Guide to Overcoming Obsessions and Compulsions Using Mindfulness and Cognitive Behavioral Therapy
by Jon Hershfield
The Habit Change Workbook
How to Break Bad Habits and Form Good Ones
by James Claiborn & Cherry Pedrick R.N.
The BDD Workbook
Overcome Body Dysmorphic Disorder and End Body Image Obsessions
by James Claiborn & Cherry Pedrick R.N.
Getting Over OCD
A 10-Step Workbook for Taking Back Your Life
by Jonathan S. Abramowitz
The Family Guide to Getting Over OCD
Reclaim Your Life and Help Your Loved One
by Jonathan S. Abramowitz
Freedom from Obsessive Compulsive Disorder
A Personalized Recovery Program for Living with Uncertainty
by Jonathan Grayson
Loving Someone with OCD
Help for You and Your Family
by Karen J. Landsman
Breaking Free of Child Anxiety and OCD
A Scientifically Proven Program for Parents
by Eli R. Lebowitz