Anyhow, I am happy that you know the difference now. I would suggest either use that site to learn more about CSS or download some good CSS templates from online and read and alter the codings and see the changes. That way you'll learn much quicker.
Here is the website which has 355 CSS templates[http://www.freecsstemplates.org/]. You can download them, open them under Dreamweaver and read the CSS coding, change the colours, text styles or sizes and preview the web page. See what best suits your need and implement into your design.
Once you get hang of it, start building your own CSS sites.
Oh and you can open these CSS template codes in Notepad++ program as well. Though you can't view them in preview mode because Notepad++ is a text editor like Notepad.
Any problems just Shout!