Chicoro's Grow It! and Going-Natural. Both mentioned above. I started detangling before shampooing and sectioning my hair because of her, and she helped me be okay with using Aphogee as a preventive measure instead of only when breakage has gotten really bad (I don't know if that's what she uses, but she was talking about using deep protein treatments as a prevention).
Going Natural gave me style inspirations and recipes to use on the hair. I loved seeing all the different things that could be done with the hair.
I have read and liked Cathy Howse's book as well. For me though, it didn't speak to me as a natural like the other two did, but I do still go to it for perusing.