Ebook: Mastering Dojo: JavaScript and Ajax Tools for Great Web Experiences (Pragmatic Programmers)

I find that the book contains mostly beginner and intermediate information. Not enough advanced topics or talking about creation the programmatic way. The layout of the book is a bit odd (Drag and Drop is only talked about for a few pages within the context of working with the Tree widget). For more advanced developers looking for more of a reference book, consider looking elsewhere.