Sigil is a free, open source, WYSIWYG program that can create and edit EPUB documents.
I use it to assemble my text and illustrative material into chapters and pages. Then I email the resulting xxxx.epub document to myself. When I check my email on my iPad, the iPad asks if I want to open that document in iBook. I say yes, and, voila, there it is, mistakes and all!
It’s a great tool for creating, editing and prototyping EPUB files. It’s an even better tool if you learn a little XML, XHTML and CSS (though they are not absolutely necessary). You can do that for free here.
I intend to list free and low-cost training resources for each software package. This will come eventually, but if I wait until everything is complete, I’ll never go live with this blog.
In the meantime, please include your favorite training resources in your comments.