The ePub format is a popular and well supported format for creating electronic publications. This is a great format to get your work on to the iPad and iPhone and most other mobile devices.
How does it work?
The system is based on XHTML and XML. Without getting into the technical details let’s just say it’s similar to creating a web page.
To create an ePub file you’ll need all of the tools you might use to create a web page, an HTML editor or plain text editor. You’ll also need something to convert your final book into a zip file.
ePub files are organized in a folder named for the book. This folder contains a few other files and folders.
A folder named META-INF, which contains files describing your book and it’s content.
A file named mimetype which defines the file type as an epub file.
The OEBPS folder, which contains all of the content of your book. This folder will contain all of the HTML pages and images that will make up the actual book. This folder also contains a CSS style sheet file to format and style your book. Two last files stored in the OEBPS folder are the content.opf and toc.ncx files. These are plain text file containing XML. The content.opf contains a list of all of the content in your book. This lists all of the HTML, CSS and image files used in the book content. For each item it lists the file path of the source file and the files type and assigns each a an id. The toc.ncx file defines a table of contents for the book. This file lists all of the content and assigns each a navPoint and playOrder. These define the order the pages are displayed in the book. Think of this as linking all of the pages together in order.
Package and compress
Once all of the HTML files and other files are completed your ePub file needs to be packages and compressed. On the Mac you can use the ePub Zip. Just drag and drop the folder containing your book on to ePub Zip.
Reading ePub books
There are several reads for ePub books. On the iPad/iPhone you can use iBooks. On your desktop you can use Adobe Editions.
Sadly the Kindle doesn’t support ePub, though there seems to be a few work a rounds that allow the Kindle read ePub.
Here’s a tutorial on creating a photo book in the epub format: http://next.blurb.com/2011/02/17/how-to-make-an-ipad-photo-book/