The Warstone Quartet series does not have a new book coming out soon. The latest book, Darkstone an Evil Reborn (Book 4), was published in February 2015.
The first book in The Warstone Quartet series, Moonstone Magic That Binds, was published in January 2015.
The Warstone Quartet series primarily falls into the Epic Fantasy and Heroic Fantasy / Sword & Sorcery genres.