I have read quite a few hair care books but here are some of my favorites:
Healthy Black Hair: Step-by-Step Instructions for Growing Longer, Stronger Hair by Nicole Elizabeth Smith. This book contains great information about caring for relaxed hair. It was such a great read, it took me two hours [or less] to finish it. I also liked that the author gave recommendations [products, vitamins etc.] that were up to date.
Beautiful Black Hair: Real Solution to Real Problems by Shamboosie. The underlying message I got from this book was that no-lye realxers are bad. In regards to my hair, I would tend to agree. Aside from 'no-lye bashing’, there are other useful bits of information presented. He gives a detailed manual on how to relax your hair [and prevent burns], he recants various true-life experiences he has had with hair and he gives product recommendations that I myself have used and can attest to their benefits.
Naturally Healthy Hair: Herbal Treatments And Daily Care for Fabulous Hair by Mary Beth Janssen. This book deals with a great amount of topics such as: methods for styling hair, tools, product etc. The thing I liked most about this book is its emphasis on products and their ingredients. It explains how products work, which ones to use for your particular hair type, what various ingredients do and how to make your own natural products.