I need to learn how to use CSS to change the layout of an HTML page. CSS is a very powerful tool for changing the way a webpage is displayed. It is extremely flexible and allows the designer to deliver HTML code to many devices without changing the markup. First I want to learn the HTML tags to create sections in the code. Next, I need to learn the box model of CSS positioning. Finally, I need to learn how to float HTML elements using CSS.

Please show me in detailed steps, how to create a HTML page that includes the requirements below.

1. The following tags are used: div, span.

2. The web page uses HTML and CSS to create a fixed width, two column layout.

3. All web pages used are styled using a common external CSS style-sheet.

4. Code Comments are used to identify the location of rubric objectives. Code Formatting is used to increase the readability of the HTML Code.