How to create second and third pages on your website?

You create a new HTML files and give them a meaningful name like about.html, products.html or contact.html Then you create links to these pages on your index.html.

The 'build a simple website' course covers these steps very well. http://teamtreehouse.com/library/build-a-simple-website

I'm guessing you are going to use Navigation i.e Home, Contact us, Etc, If so you will be making separate HTML files to make these pages so you would link these in on your Hyperlinks from the Navigation, e.g

<li class="menuitem"><a href="index.html">Home</a></li>

This would link the HTML Files and give you the link to second, third or how many you wish to have.

AND THEN to link to these html files you have created you type in the code:

<a href="linktoyourhtmlfileshere.html"></a>