There are 6 books in The Principles of Love series.
The Principles of Love series does not have a new book coming out soon. The latest book, Lessons In Love (Book 7), was published in March 2008.
The first book in The Principles of Love series, The Principles of Love, was published in July 2005.
The Principles of Love series primarily falls into the Contemporary Romance genre. This young adult series was written for ages 12-17, but can be enjoyed by adults too.