The Seven Songs of Merlin, by T. A. Barron

A nice sequel to the first book in the series. This one talks about Merlin's evolution as a wizard. He must understand seven "songs" which will turn him into a initiate in magic. The story is of course driven by higher goal: he needs to complete this quest so that he can save his mother's life, who's been poisoned by his nemesis Rhita Gawr. Good writing and very exciting pace to the story. Extremely hard to put down until you're finished.