We highly recommend you read 

Prison Ministry By Lennie Spitale is an essential book for understanding Prison Culture Inside and Out.  If you would like to further understand the challenges of this ministry, then pick up this book.  If you would like to order a copy of it for yourself, just follow this link. (click here)

Couldn't Keep It to Myself: Testimonies from Our Imprisoned Sisters 
by Wally Lamb

Ministry to the Incarcerated 
by Henry G. Covert