The Cascading Style Sheets are made up of 2 parts, the selector and the declaration.

The selector comes first and it describes the element on the page that is going to be control through this rule.

In the image below you will see the selector which will control all the h1 in the current document.

Next to the selector you will see the declaration. The declaration are contain in between these curly brackets { } which tells the browsers that all properties inside { } should be apply to the element identify as the selector (in this example h1 selector)

Inside the declaration we have the property and values. Notice they are separated by : and ends with ; this tell the browsers to move to the next property if there are any available.

In this example, our rule will take all the h1 and make them all Arial with the font size at 1.4em and the color will be white.

You can use Dreamweaver to do this for you, or if you want and you have memorialize all the selector and declaration you can always hand code them.

Find more info on Cascading Style Sheets Structure and Rules with the text links below.