The author's presentation methodology uses small text snippets of code where important lines are numbered. These highlights are matched with explanation in the text. It works very well as long as the figure is on the same page as the explanation; otherwise, page flipping results. Luckily, this does not happen often. The approach also eliminates cryptic comments in the sample code and provides a more detailed discussion when necessary.
The book covers all of the important details like cookie handling and dynamic HTML, and it then gets into AJAX basics. The latter is covered in two chapters along with a server-side discussion. This provides sufficient information to see how AJAX works, but you will still want to get an AJAX book to get into more sophisticated applications. Given the number of different AJAX development tools and platforms, this level of presentation works best because anything else would be very specific to one of these tools and platforms.
The book includes assignments with each chapter, making it suitable for class work. It also has the answers in the appendices.