Some bits and pieces from blogs which might help you with Silverlight and WPF:

• From Karsten: Using a UserControl as a DataTemplate in Silverlight
• Also from Karsten: A couple of interesting links thinking about Video in WPF: direct pixel updates in Media Element and capturing webcam in WPF
• From Peter: Dynamically loading content into a Silverlight application
• From Adam: A great three part series on creating an XBox Gamercard badge, which demonstrates the thinking behind constructing a Silverlight application as much as it does the technology itself.