The Outriders series does not have a new book coming out soon. The latest book, Expedition to Pine Hollow (Book 3), was published in September 2007.
The first book in the Outriders series, Expedition to Blue Cave, was published in January 2007.
The Outriders 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.