Hey there,
There are many books about bipolar disorder out there, and An Unquiet Mind is a good one. Go to the link below and you'll find a slew of books about bipolar disorder:
Books about Bipolar Disorder
Also, I'd highly recommend The Mindful Way Through Depression for anyone suffering from any sort of depression. It's not terribly clinical, but very helpful. Also, make sure he's seeing a therapist who uses cognitive behavioral therapy.