Although published a few years ago, one of the most useful books I keep coming back to is "Windows 2000 ADSI Scripting for System Administration" by Thomas Eck. As an IT Professional with a development background, this book has proved invaluable time and time again. Even with no development background, it never hurts to have a little more insight. Note that most of the content applies equally as well to Windows Server 2003.
Futher details are on amazon