I really enjoy reading Butterfly Books and have a nice collection of different types of books including ones about butterfly gardening, types of butterflies, how to attract butterflies, the monarch migration and more.
My three personal favorite books about butterflies are:
The Family Butterfly Book - by Rick Mikula. This is a very thorough book of photos, information and "how to" for all different butterfly topics.
The Life Cycles of Butterflies - by Burris and Richards is an absolutely beautiful book of the life cycles of many different butterflies. The photos are excellent in this informative book.
The Butterfly Book - by Donald and Lillian Stokes - This is a great resource book on butterflies and butterfly gardening.