If you are looking for one book to both learn CSS and to use as a reference afterwards then this book is one that definitely deserves to be considered.
Apart from the author's not understanding the difference between HTML and XHTML (which doesn't matter in so far as CSS is concerned) and that they leave out one whole section of CSS 2.1 that is useful for doing some page layouts (but which don't work in IE7), this book does a very good job of being all that a beginner through intermediate level CSS writer needs to know. With the introduction to CSS chapters at the front of the book, the advanced CSS chapters in the middle of the book, and the reference secion at the back, this book serves as the ideal book for anyone who doesn't want or need more than one book on CSS.
All aspects of CSS 2.1 with the exception of tables are covered in sufficient detail in this book to give the reader sufficient knowledge to achieve the desired results. The book even covers some of the sections of CSS 3 that some browsers are now just stating to support. It is a little surprising that part of the still draft CSS 3 standard is covered toward the end of the book though when one whole section of CSS 2.1 has been left out. With a chapter each to CSS floats for layout and CSS positioning for layout there really ought to have been one more chapter covering CSS tables for layout (I guess you really need SitePoint's "Everything You Know About CSS is Wrong" to supply section of CSS 2.1 missing from the missing manual).
Apart from completely leaving out one of the three ways to do page layout with CSS the book does cover all other aspects of CSS. Given that Internet Explorer 7 and earlier don't support using tables I could understand the omission except that some CSS 3 is covered in the book and IE7 and earlier don't understand that either and the CSS 3 that is covered is far further away from being properly supported by all browsers than the missing CSS 2.1 comm ands are (since the latest versions of all browsers already understand the missing CSS 2.1 commands whereas not all current browsers support the CSS3 commands that the book covers).
This article written by Stephen Chapman, Felgall Pty Ltd.