iBooks Author allows you to create and publish amazing Multi-Touch books. With galleries, video, interactive diagrams, 3D objects, mathematical expressions, and more, these books bring content to life in ways the printed page never could. Multi-Touch books can contain a wide variety of interactive elements, which makes them particularly well-suited for textbooks, cookbooks, history books, and picture books. Apple Books only accepts Muti-Touch books made with the latest version of iBooks Author.
The iBooks Author support site includes best practices for audio, video, fonts, 3D objects, accessibility, and more:
https://support.apple.com/HT202374 – Add video or audio to your book
https://support.apple.com/kb/PH2791 – Add a movie or an audio file
https://support.apple.com/HT204133 – About the Keynote widget
https://support.apple.com/HT204433 – About HTML5 widget creation
https://support.apple.com/HT202929 – About link creation
Note: Multi-Touch books require a custom sample for previews. See Samples for Books Created with iBooks Author for details.