The presentation is quite clear with a discussion and detailed description of each 'recipe'. It can be somewhat dry reading unless you are able to try out the examples. A few more pictures would also have been helpful. All the sample code is available for free download on O'Reilly's web site.
There are 15 chapters in 522 pages that cover a broad range of subject areas. It starts with simple concepts like variables, arrays, functions, etc and then goes into more detailed examples. Some complete libraries of useful functions are provided, such as cross-browser positioning of HTML elements, creating custom scrollbars, etc. There is quite a large section on creating custom menus in various styles.
The discussions recommend good site design practices, such as not opening sub-windows and supporting all the common web browsers. Mac users are not excluded either.
I thought that this book would be very useful for anyone creating their own dynamic web sites. I did not have time to try out many of the examples, but the source code looks to be well written. It is well commented and described, so it should not be too hard to customise for your own personal requirements.