Matthew Johnstone has written three books that I have found useful, the first is I HAD A BLACK DOG which with illustrations takes you through the feelings and expereinces you might have with depression. I found this useful particulalrly in terms of knowing that there are other people out there expereincing the same feelings. His second book LIVING with a BLACK DOG is a great book for family members to help understand what is going on and specfically what is helpful and what is not helpful to a sufferer of depression. His third book QUIET THE MIND starts you on the subject of meditation which is an area I have found very usueful and continues to help me greatly. Below are links to each book and if you buy any of the books using this link will earn me a few pennies.
I hope you find Matthews books as useful as I do.