Pressbooks is simple book production software. It allows you to write a book using the sofware or import a manuscript, choose a book design theme, and export into all the file formats you need to publish your book:
Pressbooks is used by authors and publishers around the world (Pressbooks, 2017, para. 1).
For online tutorials that teach you how to use Pressbooks, visit the following YouTube channel: https://www.youtube.com/user/pressbooks