Take it to the next level - Creating Talking eBooks in PowerPoint:  

Now that you know how to convert a PowerPoint slideshow to PDF, try these additional strategies to make Talking eBooks
  1. Under the Slideshow tab, add Action Button arrows to create page turners
  2. Insert animations and videos in PowerPoint
  3. Add voice recordings in PowerPoint
  4. Record the PowerPoint to create a viewable eBook
Read this article: Creating eBooks with PowerPoint by DrsCavanaugh

Other technologies for creating eBooks:  
  1. Save as a PDF in Microsoft Word
  2. Export as PDF or EPUB in Apple Pages
  3. Upload to Issuu (teacher only) to create eBooks that appear as digital books online or embedded in your blog, wiki, or website
  4. iBook Author Mac app to create multi-media, interactive eBooks on a Mac for reading on a computer or iPad | Read the iBook FAQ
  5. StoryBuddy App for iPad
  6. StoryBuilder App for iPad
  7. Higher end: Calibre

  Read this article: Create your Own eBook for the iPad by Langwitches