I found some interesting reading in the Yahoo "Prius_Technical_Stuff" forum.
Here are a couple of reports distributed by the Oak Ridge National Laboratory. Be cautious in that a few technical inaccuracies have been pointed out, such as the false assertion that the Prius has a turbocharger.
Evaluation Of 2004 Toyota Prius Hybrid Electric Drive System Interim Report
Report On Toyota/Prius Motor Design And Manufacturing Assessment
and here's a website where the owner has put together a lot of good explanation of his "Classic"
Al