These are some books that are out there about self injury.  The "reviews" for lack of a better word, are mine, I will add those that i haven't read and quote where the review comes from.  if there are any books that i have missed, please let me know...
Marlee Strong  A Bright Red Scream:  This is an incredible resource.  Strong does a wonderful job of including medical termonology without making you feel as if you are reading a medical dictionary.  She interviewed many woman to include in her piece.  It has facts as well as personal stories. 
Steven Levenkron  Cutting: This is taken from the perspective of a psychologist who feels he is a "pioneer" in treating patients who self injure.  I enjoy the factual information and how he stresses the patients are NOT crazy, but i don't feel that he gives his patients enough credit, nor does he except that sometimes self injury just happens, there is no reason.  i also think he gives himself a little TOO much credit. 
Karen Conterio and Wendy Lader  Bodily Harm:  This is written by the people who run SAFE (Self Abuse Finaly Ends).  The book is incredible and includes self assesment.  i would recomend everyone reads this one.  While i do not believe in their philosophy that self injury is an addiction, but still, the book is well written. 
Armando Favazza  Bodies Under Siege:  Great book for technical information, but its sometimes very hard to understand.  Still as a resource, its a must read.  He is the pioneer in the study of self injury.  Very technical, but still full of info that one must read. 
all these books and more are available online with amazon