Good Pictures, Bad Pictures by Kristen A. Jenson, MA and Gail Poyner, PhD illustrated by Debbie Fox*

I first heard about this book via Focus on the Family.
Although this book is divided up into chapters (topical), there is an ongoing dialogue between a boy and his mother about pornography.  The mother discusses with her son what pornography is, the parts and functions of the brain, what an addiction is and how it affects the brain.  She also shares some steps what to do if one sees an pornographic image.
I found this book extremely helpful to provide an avenue to talk to my boys about pornography.  I really appreciated how it incorporated the science behind an addiction.
*Highly recommend.
-Borrowed from a friend.