Just a few notes about the SECOND edition (of which the publisher was kind enough to send me a review copy): Judging from descriptions by reviewers of the first edition, this seems to be a considerably enhanced second edition, addressing complaints described here.
The book is easy to look through and use as a reference. The preface describes the target audiences as already "web authors" who want to become more effective. If you are completely new to CSS, the book does a nice step-by-step education of the ins and outs of CSS. However, if it had been my first CSS book (instead of 6th), I'm not sure that I would have had the motivation to learn how to convert all my planning from simple HTML markup to CSS; that I got most persuasively from Owen Briggs' "Cascading Style Sheets: Separating Content from Presentation" ISBN 1904151043, which I highly recommend to anyone still just mixing CSS into their HTML for occasional convenience. Nor is the writing engaging enough to carry along a reader who is not already convinced that they have GOT to learn CSS.
"Core CSS" does provide pretty comprehensive reference material, although some of it will not become "pragmatic"(the stated objective) for a few years -- e.g., all the material on CSS-3. The author usually includes the caveat "proposed" before the term CSS-3 ( the standards are still developing). Three years from now when browsers start to attend to CSS-3 standards, this material will apply (or be outdated if final standards different). Anyway, for CSS newcomers the inclusion of all the not-yet-applicable CSS-3 material will probably be more confusing and distracting than useful. More "pragmatic" to me would have been the inclusion in the extensive browser-compatibility tables of Apple's Safari browser (i.e., Mac OS X). Safari's user base is closing in on 10 million; it is the fastest and arguably most convenient browser yet designed; and although Mac users are a minority, their ranks include above-average incomes (and hence web shopping, etc.) and a preponderance of designers (including web).
My other concern about attempting to present "Core CSS" as an all-in-one CSS is that it does NOT have examples of how to WORK AROUND the documented quirks introduced by the pervasive disregard by browser designers for CSS standards. Here is where ANY CSS designer needs to study a copy of Eric Meyer's "Eric Meyer on CSS: Mastering the Language of Web Design." The latter volume enables a designer to see how/why to employ CSS from scratch in designing pages/sites and special strategies for REdesigning to maximize efficiency for author and visitors.
I'm not one to encourage monopolies, yet I must say to the beginner that once Meyer's volume has given you the strategies to design with CSS, Meyer's reference volume (0072131780 - Cascading Style Sheets 2.0: Programmer's Reference) continues to be handier to work with as a daily-basis reference than "Core CSS" - even including basic conceptual frameworks such as the "box model" in a way that helps your planning (despite being two years older). Although "Core CSS" includes some screen shots, they do not offer as strong a conceptual underpinning for beginning one's work with CSS. My apologies to the publisher for a tepid review of Core CSS: it is improved over the first edition; but it doesn't amount to either an effective introduction for beginners or a comprehensive 2004 reference for the experienced.