There is a lot of very good material in here but it's spread over way too many pages.
It appears that the "Try it Out" sections were added after the book was written simply to increase the page count. They are poorly integrated with the text and, to add insult to injury, the author (or, more likely, the goober in charge of page counts) urges you to bring up your text editor and type in the example simply to illustrate a minor point. (What is this, a typing course?)
Another annoyance is that the author keeps bringing up the fact that such-and-such browser will not work with this-or-that feature of this-or-that version of CSS. Here's an exact quote from page 73: "The upcoming sections (through to the section titled 'Attribute Selectors')are CSS 2 selectors, which are not supported by IE 6." After a series of admonishments like this, you become paranoid that no past or future version of any browser will work with your style sheet (and consequently you will be made sport of in web development circles.)
My advise for the third edition: Cut the length in half. Get rid of the try-it-outs. Put all caveats, admonishments, warning labels, and eviction notices in one chapter or appendix and be done with it.
Then it will be a great book.