If you're learning from scratch, the first thing I would do is go to w3schools (http://www.w3schools.com/css/default.asp). I swear by them as a tool for learning the basics - as for actual coding, they have "Try it yourself" options throughout their lessons.
Wow! Never seen that before. I get the point, though most of their concern seems to come from very nitpicky things, as well as javascript, which I wouldn't point someone to w3schools to learn. I stand by the claim that it serves the purpose of learning basic HTML+CSS.
