The Dark is Rising and Greenwitch by Susan Cooper

This is an old series--and I skipped the first one in the series unintentionally. The Dark is Rising travels across time as it tells the story of the Light versus the Dark. Will, a young British boy, is a warrior of the Light who is the key to their final victory against the dark in the war ancient and powerful beings have been fighting for centuries. Will is a great protagonist who loves his family, wants to do what is good and learns quickly how to play his role as a warrior. He succeeds in getting all 6 of the "signs" and learning his place of power among the immortal Old Ones. In Greenwitch, Will joins with Merriman's niece and nephews in a search for the golden grail that has been stolen by the Dark. They also witness the creation of the "greenwitch" used by fisherman in a seaside village to bring good luck. These all combine as Will and the Old Ones continue to battle the dark.

I think this series is great, though a little complex at times to follow. It was written in the 1970s but didn't become really mainstream until they made a movie out of The Dark is Rising. It preceeds Harry Potter, and I might venture to say is slightly more enjoyable. It mixes pagan myths with ideas of Christianity, but does not outwardly promote either--it focuses more on the idea of Light beating the Dark. If you love fantasy and the classic struggle between good and evil--think Lord of the Rings, Harry Potter and The Lion, the Witch and the Wardrobe-check out this series.