This book is a disappointment on three very different aspects, the weight of the book, the HTML style presented and the surfeit of poor reference material.
A book is a medium that is to be handled while being used. At 1020 pages, I found that I could not read the book for long periods away from my desk, as the weight put a severe strain on wrists and arms. On the positive the binding did stay open at the required page when laid flat.
The authors do not quite make the jump to XHTML; they describe XML requirements and how this impacts on HTML (well formed, closing tags, etc.), but spend many pages describing deprecated features of XHTML. In fairness they do point out that these features are deprecated and refer to the CSS chapter. I would have preferred the authors spend more time on the CSS and less on the old HTML.
So far I have covered just the first half of the book. The second half is reference material, lifted from the W3C site and 'un-hyperlinked', so every tag has 3/4 of a page describing the class, id style and title attributes, over and over again. This material ought to have appeared in an accompanying floppy or CD (which would have removed the weight problem, as well as making for easier reference).
The HTML (sic) they present would appear to be accurate and the first half of the book could be useful, but check out other books and consider the weight before you buy.