CSS in 24 Hours is a book by Kynn Bartlett that helps anyone that needs to learn how to do cascading stylesheets to pick up the basics in a very short period of time. A book that's almost 450 pages might not seem like it'd be the type to help you learn it in 24 hours, and truthfully it might take some people a little bit longer, but I pretty much learned the basics within a few hours.
What makes the book easy to use is that the writer not only gives you a bunch of examples in the book, but he gives you a link in the book that you can go to and download files to look at and play with. I found the hands on files, as well as the book, helped me to pick things up much faster than had I had only one or the other.
A bit of a reality check is that you can get really deep into the bowels of CSS, but pretty much everything you need to learn to get started is within a few specific chapters, which he calls "hours". For instance, hour 4 teaches one how to use CSS with HTML; hours 9 - 13 talks about fonts, colors and links. Formatting comes in hours 15 and 16, and an overview of web design comes in hour 21. With the forms support from the downloads, it shouldn't take anyone who already knows a little bit about coding much time at all to learn.