LiveCycle Designer is used for designing Forms, not eBooks.
The requirements of designing a book (ebook or otherwise) are not going to be meet by LiveCycle. You need functions like pagination and indexing.
A better choice would be to use InDesign, or even a word processor like Microsoft Word, and convert to PDF when finished.
You can read more about eBooks and the Adobe Digitial Publishing Platforms here: http://www.adobe.com/digitalpublishing/ebook/
At the bottom of this webpage are Resources which may help you understand the requirements of digitial publishing.
Hope this helps,
-Michelle