my treatment provider doesnt use any special books. she learned the things we do through workshops, seminars and through her educational and job training along with her own interest in things like relaxation, stress reduction, mindfulness, and of course her hands on work with clients.

my own personal favorite books for grounding and mindfulness are "mindfulness for beginners" by Kabat Zinn, A mindfulness based stress reduction workbook by Elisha Goldstein, and I will try just about any guided meditation at least once,

there are many great books on DID, whether they are good or not depends upon what you are looking for, when I first joined psych central I also found many great books in the resource thread that Doc John has going here http://forums.psychcentral.com/showthread.php?t=71992 that my therapist and I found that were helpful during my integration process so that I would be more comfortable with myself, my alters and the whole process I was going through. some of them had stuff on all types of alters.