I've done extensive work with CSS, XHTML, and DOM scripting, and I haven't purchased a single book - I find that the internet resources for syntax and built-in functions and free tutorials on various techniques that people have written (some more high quality than others, but I have never failed to find a good tutorial for what I've been interested in.) more than suffice. However, if you're really looking to get a unified, extensive lesson, that book looks as good as any.