It's really hard to write a decent book on Wicca beyond "Wicca 101" unless one is writing from an anthropological or sociological perspective. Kirk White, however, has managed to do just that. It's not perfect, but what is?
The book starts with a review of basic material, but even there he goes into somewhat more depth than you might want if you were brand-new to Wicca. Later, the book covers much more advanced material, up to and including "Deity Work and Divine Possession." Definitely worth the read. ( )