The course is both useful for people that don’t know anything about web coding and for html/css gurus.
If you don’t know anything about web coding, the course is pretty easily explained, you will learn quite easy. However, you might get stuck if you are not familiarized with the HTML and CSS terms and have to google the results or more hints.
If you are pretty good with HTML and CSS, this course will do just fine to clarify some things that you might know but you don’t know exactly how they work or how they work in a certain way.
Like for example that the padding values on the same line are working clockwise: padding-top, padding-right, padding-bottom, padding-left.
There is some useful information regarding the display option for css, floating and how to deal with them.
Anyway, if you want to get better with coding and be certain that you are progressing, this course is great.
If you are stuck anywhere, leave here in the comments and I will help you.
The course can be found here: http://www.codecademy.com/learn.