It treats HTML and XHTML as the same thing, only distinguishing one from the other when a specific point needs to be made. This was a nice way to start as it removes the mystery of XHTML and allows the reader to concentrate on getting things displayed. I was also interested in the way the book worked from basic structure to applying ids and classes without introducing styles. These aren't introduced until chapter eight where you (hopefully) already have a feel for basic structure, layout, and markup.
The book races through the easier parts of HTML and I guess it could be possible for a complete novice to get lost, so pay attention in the first chapter. The book is rated for 'intermediate users' though, so complete beginners may want to be wary. The good news is this leaves room at the end for bonus content like character encodings, problem solving, marketing and RSS.
It is easy to see why this is a popular web design book. Topics are laid out in a no-nonsense manner that makes everything look easy and achievable, there is plenty of content without being heavy, and the layout provides the flexibility for colored examples and additional points of interest. Also, don't overlook a web book that is printed in color!