She-Ra and the Princesses of Power: Rebel Princess Guide is a guide book to the animated series and the world of Etheria. Released on September 3rd, 2019, it belongs to a collection written by Tracey West, and was published by Scholastic Inc.
The book is primarily written from Adora's point of view and is framed as a study guide she has created for herself based on notes she has taken during her adventures. On page one of the book Adora says: "Right now, I have no idea how to be a princess or control my powers. But one thing I learned in the Horde is how to study. I am going to pay attention, take notes and train from sunup to sundown, I am going to slay this princess thing."