I've written this book for the folks who actually use Windows Server 2003. If you use Windows Server 2003 in any environment, you most likely already have a basic knowledge of the operating system and how it works. So that fundamental knowledge is assumed in this book.
I jump straight into the topics of interest in the security area. However, I don't assume you have a deep architectural knowledge of every Windows component and subsystem. So, when appropriate, I use diagrams and flowcharts to help illustrate security-specific features and components that you may not have encountered.