The Julia Gillian series does not have a new book coming out soon. The latest book, Julia Gillian (and the Dream of the Dog) (Book 3), was published in July 2010.
The first book in the Julia Gillian series, Julia Gillian (and the Art of Knowing), was published in June 2008.
The Julia Gillian series primarily falls into the General Fiction genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.