Make the eBook on the iPad and publish it out to the iBook Store. You could also sell your eBook though an aggregator like Lulu or Smashwords. It can be sold by directly dealing with Apple if your know what you are doing and will buy your own ISBN numbers.

1. Creating eBooks
Using the iPad to create your eBook
Publish direct to the iBooks App or Sell Your eBook

2. Choose your App
Creative Book eBook Demi Books
Book builder Creator Magic Composer
Creative Book Builder, Book Creator and eBook
Magic Are apps that will make ePub book that will
go into the iBook Store.
Demi Books Composer makes books in as an
application to go in the App Store

3. Create Your Book Cover
Drop in a photo and put some text over it

4. Add your content - Photos and Text
Would be good to be able
to rotate images but not
possible in Book Creator
Book Creator -
Limited capabilities for
formatting text

5. When Done Export Out to iBooks or DropBox

6. Publishing on Lulu
Not that difficult
to get published

7. Make your Ebook on the iPad
Read it on the iPad
Sell it in the iBook Store

8. Read more about using the iPad
The Amazing iPad
WebSite
http://amazing-ipad.com