Helpful WMI Documentation
Some parts of Windows Management Instrumentation's (WMI's) documentation are easier to get through than others. Here are some areas within the Microsoft Developer Network (MSDN) Library (http://msdn.microsoft.com/library/default.asp) that are helpful. I've included not only the URLs but also the navigation instructions in case the URLs change.

WMI Basics
URL: http://msdn.microsoft.com/library/default.asp?url=/library/psdk/wmisdk/appprog_ 3bfp.htm

Navigation instructions: Platform SDK, Management Services, Windows Management Instrumentation, WMI Application Programming, Programming Basics for WMI Applications, Retrieving a WMI Class Instance

WMI Classes
URL: http://msdn.microsoft.com/library/default.asp?url=/library/psdk/wmisdk/hmmclass_00j7.htm

Navigation instructions: Platform SDK, Management Services, Windows Management Instrumentation, WMI Reference, WMI Classes.