There are many self-help paperbacks already published on self-injury that are readable, helpful and under $15. "Treating Self-Injury" is written like a textbook but it is the most organized and comprehensive of all that I have seen. I would recommend it especially for school personnel or therapists who have little experience with "cutters" or those who cope through other forms of self-injury. The text would aid senior clinicians in intergrating various models into a coherent approach for treatment.
Too many times, self-injury is confused with suicidal ideation and this book helps to dispell a lot of old myths. Mr. Walsh has done considerable research in synthesizing what has already has been written and wrote a "bill of rights for people who self-harm" against those myths. This is not a book that will be read in one sitting but one that the reader can consult and review. A more readable approach, though more narrow and less comprehensive, is "Cutting" (1999) by Steve Levonkron (as a matter of full disclosure, I once did a workshop with Mr. Levenkron years ago).