Resource for SharePoint Site Definition
Deciding Between Custom Web Templates and Custom Site Definitions http://msdn.microsoft.com/en-us/library/aa979683.aspx How to: Create a Custom Site Definition and Configuration http://msdn.microsoft.com/en-us/library/ms454677.aspx Understanding Web*Temp.xml Files http://msdn.microsoft.com/en-us/library/ms447717.aspx Understanding Onet.xml Files http://msdn.microsoft.com/en-us/library/ms474369.aspx Customizing Site Navigation http://msdn.microsoft.com/en-us/library/ms471078.aspx How to: Create a Custom List Definition http://msdn.microsoft.com/en-us/library/ms466023.aspx Creating Content Types http://msdn.microsoft.com/en-us/library/ms479905.aspx How to: Add a Document Template, File Type, and Editing Application to a Site Definition http://msdn.microsoft.com/en-us/library/aa978104.aspx