For a description of the version of the Mac OS that comes with the new models, you should refer to the technote for Mac OS 9.1. Other technotes contain information about the NewWorld software architecture and the API changes for Power Manager 2.0. The technotes are available on the Technote website at
http://developer.apple.com/technotes/
You should also have copies of the relevant books describing the system software for Macintosh computers available in technical bookstores and on the World Wide Web at
http://developer.apple.com/documentation/mac/mac.html