CSS stands for "cascading style sheets." It is the thing that will change the display of your HTML, from your font size and style to your background and header color. It is what will make your website look pretty, as long as you make the right design moves.
You will need Text Wrangler or Notepad ++ again for this.
We'll start off with something simple. Like the body of the page you are making. If we aren't getting fancy with a separate header or footer, then what we are dealing with is the background of the page and everything on it. We'll go with the background color here and changing the font.
Open the wordprocessor of your choice and before starting anything, save it -- "name of file".css (remember to save it as css). Then input:
Within these tags you can go even further. Instead of typing out the color you want to use you can use color codes. These will work for both the background color of you page and the text, aside from links, on your page.
Once you have finished setting up your CSS you can go into your HTML file and link your stylesheet between the title and head tags:
To use what you have created in the stylesheet this is where divs come into play. Within you html you will input:
Now that you've got everything down, go out there and create your website! If you didn't quite get it you can start off again at the beginning.
