This weekend CodeScool corser where available for free, I heard lots of good responses about its Rails-related courses, and decided to take opportunity and try CSS course http://www.codeschool.com/courses/css-cross-country
Although it's too basic for me, it done really well and I believe it should be a really good start point for beginner. Take also look at CheatSheet for CSS styles used in Bootstrap http://alexeypetrushin.github.com/cheatsheets/css
