SQL Server 2005/2008 System Views Map
Excerpt from the Microsoft Site:
The Microsoft SQL Server 2008 System Views Map shows the key system views included in SQL Server 2008, and the relationships between them. The map is similar to the Microsoft SQL Server 2005 version and includes updates for the new and updated the Microsoft SQL Server 2008 features such as resource governor, extended events, full-text search, and others.
You can download the SQL Server 2008 version from:
There is an equivalent one for SQL Server 2005: