1. Log in to your SiteBuilder administration section
2. Click on "Settings"
3. Click "SEO Options" on the left side
4. Click on the "Statistics" tab
5. Put a checkmark to add the tracking code and in the text box paste in the textbox the javascript that your stat tracker has provided you.

Third party web statistics such as Google Analytics will provide you a snippet of Javascript which you could enter in step 5 above.  In fact, any web statistics system that requires you to insert a piece of javascript on your site can be used in this same way.