Highly recommended. With html + css, there are many ways to do different things (tabs, font sizing, etc.). This book gives you the "best" and most "bulletproof" way based on the author's own experience as a web developer.

Quoted: Each chapter starts out with an example of what Dan refers to as an “unbulletproof” concept—an existing site that employs a traditional approach and its associated pitfalls. Dan then deconstructs that approach, noting its downsides and then making the site over using Cascading Style Sheets (CSS). By the end of each chapter, you’ll have replaced traditional, bloated, inaccessible page components with lean markup and CSS. The guide culminates with a chapter that pieces together all of the page components discussed in prior chapters into a single page template.