Apple has announced iBooks Author at the education event in New York. iBooks Author will allow you to create books within Mac OS X for digital distribution through the iBookstore.
You can select from a number of templates already created for you or import your existing content. iBooks Author is made to compliment and work nicely with applications such as Word, Pages, and Keynote. You can even turn Keynote presentations into widgets within your book.
iBooks Author will be available today as a free download in the Mac App Store.
Free - Mac App Store Link