Here is a great resource about SilverLight development on SharePoint 2010:
Include sample code and a video explaining how to develop with SilverLight for SharePoint 2010. Including topics like: SilverLight WebPart development, SilverLight field controls development, the use of the HTML bridge to pass data between SilverLight WebPart and the web page. And last but not least: how to connect SilverLight WebParts with no page refreshes and using the standard WebPart connection mechanism.
Also a sample making use of the new restfull access to SharePoint lists using ADO.NET services.
A must read for those who are starting developping with SilverLight on SharePoint 2010!