iBooks Author is a free app available in the App Store on your Mac that you can use to create and publish ebooks. Using the tools in the app, you can add artwork and metadata to a book. You can also open .ePub files that you created in a different program to iBooks Author, and then sell them on the iBooks Store or distribute them for free.
To publish your book from iBooks Author, you must first export it as a PDF, text file, .ePub, or .ibooks file. To choose what format is best for your book, first decide how you plan to distribute it.
Publish your book on the iBooks Store
You can create a book in iBooks Author in ePub (.epub) or iBooks (.ibooks) format and publish your work to the iBooks Store. You can also use Pages to create .ePub files.
Publish your book for an iTunes U course
To submit your work for publication on iTunes U, save it as an .ibooks or .ePub file.
To publish your book on iTunes U, you must have an iTunes U site. If you don't have an iTunes U site, you can apply for one.
Distribute your books on the web
You can distribute works that you create with iBooks Author on the web as a standalone purchase or subscription product or service. When you sell your book on the web, it must be in a non-iBooks format (.ibooks). Examples of a non-iBooks format include PDF and ePub. If you wish to sell your work in the iBooks format, you can sell it only through the iBooks Store. When you provide a work for free, you can distribute it in any format (including .ibooks) through the iBooks Store or by other means.
You retain all of your rights in the content of the work that you create in iBooks Author. If you distribute your work in .ibooks format, it's subject to the distribution restrictions described above.