This document provides instructions for creating a custom site definition in Microsoft Windows SharePoint Services. It includes 4 exercises: 1. Copying the default site definition and modifying the site definition XML file to reference the new custom definition. 2. Modifying the menu bar for sites created with the custom definition. 3. Adding custom client-side script commands to the user interface. 4. Creating a new site based on the custom site definition. The goal is to learn how to customize specific appearances and behaviors for sites created with a new custom site definition in Windows SharePoint Services.