I love books and have mountains, and always enjoyed going back and referencing through a good book. Personally I keep a copy of Indoor Marijuana Horticulture by Jorge Cervantes next to me when assisting with technical questions. Its old, but I like it cause I know the book well and easy to access answers.
For beginners I would suggest Marijuana 101 as a cool coffee table book that really just covers that basics of home gardening.
Below are a couple of my books still sitting in the office my girlfriend annexed. Favorite book is Mr Nice signed by Howard Marks.
My all time favorite is the The Cannabis Grow Bible by Greg Green.