CSS Style Sheets
Before you can do some actual CSS coding, you need to know where to type in your CSS codes.
There are two ways in which you can do this.
External Style Sheet
The first (and probably most ideal) approach is to create an external style sheet. This is basically a plain text file that you save with the .css extension. Within this file is where you'll be doing all your CSS coding. You type in whatever CSS code formatting you want directly in this file. When you use an external style sheet, every one of your web page that reference this style sheet will conform to its formatting. So if you update your style sheet file then every page that reference it will also be updated.
Linking External Style Sheets
Once you have a completed external style sheet with all the CSS codes that you wanted, you then have to link it to each one of your web page where you want it take effect.
Here's how to do it:
In the header section of your page, type, <link rel="stylesheet" type="text/css" href="URL location of where the CSS file is stored" />
Internal Style Sheet
The second way is to create an internal style sheet. If you choose to use an internal style sheet, then you'll be doing your CSS coding within the <head> section of a web page. Keep in mind that an internal style sheet will only affect the web page where it was written in. So if you wanted to use the same formatting and the same style on multiple web pages, then you'll be better off using an external style sheet instead.
To create an internal style sheet, you type into the header section of a web page:
<style type="text/css">
</style>
Then you type in whatever CSS code that you want in between these two tags.