When Simon, Jane, and Barney found an old manuscript while on holiday, they had no idea that it would put them in the center of the timeless struggle between good and the dark. Now they must race to discover where the manuscript leads before the agents of the dark can find out and it's too late.
Over Sea, Under Stone is the first of five books in The Dark is Rising Sequence. It's a light read aimed at elementary school age readers. The story contains some mildly scary situations, something like hypnotism, keeping information from parents, and at least one instance where it is implied that someone said a not nice word. There is no profanity (in English at least), sexual content, killing, or real violence.
Interesting Note: The tone and beginning reminded me strongly of C.S. Lewis' The Lion, The Witch, and The Wardrobe and there are several similarities early on – although the stories are actually quite different.