★★★★★ HTML Mastery: Stemantics, Standards, and Styling by Paul Haine (Friends of Ed, 2006) is different enough to be desirable as an addition to your library. It takes on some new ideas regarding HTML and has a different slant from most other HTML books.
Paul Haine writes like a teacher. His style is careful, clear, and well planned.
There’s a strong emphasis on semantics in HTML in this book and some very good suggestions and ideas to add to your approach to HTML. Chapter 2 on Using the Right Tag for the Right Job and Chapter 6 on Recognizing Semantics were especially informative.
There’s an interesting chapter on microformats, such as the hReview microformat being used for this review. Other information not usually emphasized in an HTML book includes a chapter on XHTML 2.0 and Web Applications 1.0, an appendix on how to serve XHTML as XML, and an appendix on alternatives to frames.
Overall, an excellent book with a new slant.