The Seven Citadels series does not have a new book coming out soon. The latest book, The Seventh Gate (Book 4), was published in October 1987.
The first book in the Seven Citadels series, Prince of the Godborn, was published in July 1987.
The Seven Citadels series primarily falls into the Fantasy genre. This young adult series was written for ages 12-17, but can be enjoyed by adults too.