I'm really new to the scene myself so maybe my experiences will help you; from one beginner to another. So far, the best method I have encountered to ‘learn CSS’ is through various YouTube tutorials. I have also looked at a few sites that provide PSD files, so you can basically open them up, and try to convert the whole thing into CSS/HTML, this has enabled me to learn so much over the last few days and things are actually sticking in my memory as I’m using the CSS first hand.
One method of learning which has given me the very basics of CSS is the online tutorials at www.codeacademy.com. I know this doesn’t answer your question specifically, but I personally have purchased four books in total and spent around £70 on them, and have barely used them since trying the YouTube ‘Hands on’ method. If you want some links to the best YouTube videos, send me a message and I’ll be more than happy to send them in a PM as I’m not 100% sure what the rules are here for posting links,
Hope this helps!