The Microsoft SQL Server 2008 System Views Map shows the key system views included in SQL Server 2008, and the relationships between them.
It is available in PDF or XPS format.You can download them.
http://www.microsoft.com/downloads/details.aspx?FamilyID=531c53e7-8a2a-4375-8f2f-5d799aa67b5c&displaylang=en