It depends on your learning style - do you want a book that you can write notes in and refer back to, or do you feel more comfortable keeping everything on the same screen? There are plenty of good books out there that are not that expensive. Head First HTML & CSS is a great resource that I highly recommend.
Regardless of which one you choose, the best thing you can do to learn CSS quickly is to dive in and try stuff. I started learning HTML and CSS about 2 years ago, and when I started I spent 15 hours/day staring at code. This is a little extreme, but it was effective.
Another option in addition to books/tutorials is to look at source code of websites that are out there to see what they're doing. A good resource to do this is Firebug, a Firefox extension that has a "light" version that will work in other browsers.
The last piece of advice I have to offer is don't be afraid to ask questions. There are plenty of resources out there for you if you want them, and lots of people happy to help. Good luck!
answered Nov 27 '12 at 10:52
The most efficient way of learning anything is to have to teach it!
answered Nov 07 '12 at 10:45
Personally, I like to use an e-learning website as it is generally cheaper. I recommend taking a look at W3Schools as they do provide some very good tutorials for CSS.
Here is the link for the CSS tutorials: http://www.w3schools.com/css/default.asp
I hope this helps!