The creation process entails building a HTML5 page with a fixed width (768 pixels), and then adding all the elements that you want to it. A folder containing all the files to go with that page will be automatically created.
And note that it is not necessary to have an iPad in order to use Baker. You can actually use it from your desktop computer, and the provided simulator will let you see what the book that you are creating will look like on an iPad.
Other than that, it must be said that Baker is an open source project, and that the site includes examples that you can check in order to ensure doing things right. So, getting your ebooks together should not be that problematic at all.
BakerFramework.com In Their Own Words
Baker is an HTML5 ebook framework to publish books on the iPad using open web standards.
Why BakerFramework.com It Might Be A Killer
iPads have been around for some time now. Their true potential and practicality is being realized. Applications like this one will be in more and more demand as each day goes by.