Ariesp, just being there for him will be a lot of help to him, none of us like being alone with this and an understanding partner is a truly wonderful thing for him.
There are many books about the transgender condition and the generic one which I always recommend is "True Selves: Understanding Transsexualism--For Families, Friends, Coworkers, and Helping Professionals"
http://www.amazon.com/True-Selves-Understanding-Transsexualism---Professionals/dp/0787967025/ref=sr_1_5?s=books&ie=UTF8&qid=1339011104&sr=1-5
Another one which you might like to try (although I have not read it) is "Becoming a Visible Man" by Jamison Green (http://www.amazon.com/Becoming-Visible-Man-Jamison-Green/dp/082651457X/ref=sr_1_1?s=books&ie=UTF8&qid=1339011520&sr=1-1)
I am sure Cole will be pleased to advise yoy as well
I hope everything goes well for you both
Carol xx