Previously created websites can be imported directly into the Book module. Books can be printed entirely or by chapter.
The book module allows you to have main chapters and sub chapters, but it goes no deeper. In other words, sub chapters cannot have their own sub chapters, as the module is intended to be a simple resource for teachers and students.
The book module is not interactive. You can, however, link to choices, forums etc., from within a book. Also, Flash movies and other multimedia may be included in a book.

Read more about the book module in the official Moodle documentation.