Nekoshema is right, Cunningham is a big authors. He is also one of the authors that pretty much every Wiccan tradition will have on their pre-initiation reading list. My tradition has, Living Wicca, Wicca in the Kitchen, and Wicca: A guide for the solitary practitioner, on ours as they are great introductory books.
If you're looking for really awesome magickal references, I would also suggest Drawing down the moon by Margot Adler, Buckland's Complete Book of Witchcraft, Aradia: Gospel of the Witches, A Witch's Bible (By the Farrars), and The Spiral Dance by Starhawk (I'd suggest getting a newer addition as it is quite a bit different).
Best of luck in your book search!