Documentation for the Schedule Performance Analyzer and the Project Status Reporter are available here for downloads.  The documentation covers the following topics for each plug in:

1. Operating Instructions: Step-by-step instructions on how to run the macro against your MS Project^TM schedule.
2. Set Up: The steps to prepare your schedule for optimal use of the plug in.
3. Practice:  A "how to" guide on practical application of the tool to your project.