Following up on Ivan Herman, whose name I suggested in the Elluminate chat area a week ago. Here is the link to the slides "How does the Semantic WEB work?" he presented at a talk at the “Semantic Café” event in São Paulo, Brazil, organized by W3C Brazil Office on 15thOctober, 2010.
If you scroll down his page there are a number of other presentations he made on the Semantic Web.