Does the series h2o have a book series?

Upside down caper

No it's not. The Prince of Persia film was based on the game.

Series of books means that there is more one book and that they share relation. Usually by the same author.

Pokemon adventures they have about 50 volumes already

Wicked: The Life and Times of the Wicked Witch of the WestSon of the WitchA Cowardly WarOut of Oz