Today I am reading Harry Potter's Bookshelf: The Great Books Behind the Hogwarts Adventures.
I stumbled across this enlightening work by John Granger while browsing the offerings at Library2Go, Oregon's Digital Library Consortium. Granger's analysis reveals ten genres and four layers of meaning in J.K. Rowling's amazing books. She disclosed in interviews that she planned the seven novels for five years before writing the first one.
I recommend HP's Bookshelf for a thought-provoking revelation of the depth of literary allusions and mystical meanings in the Harry Potter books.