General Questions

I am trying to port my WinForm app to Silverlight 4.

This is pretty tough going.
I have two initial questions:
1. How can I cause the ellipse to actually appear in the palette? I've set the Figure to NodeFigureEllipse but I assume I need to define it somehow as a resource? Where is this documented?
2. Once the nodes appear, how can I allow for dragging a link from one node to another in the diagram? The ellipse nodes should all for "many" in and "many" out - no limit. I control the limits when a link is attempted.
My app is very much like this - except the links have arrows and there's a palette to the left:

You might want to start with the ForceDirected layout (FDLayout) sample. Its nodes are basically ellipses and the user can draw as many links as they want from any node.

It doesn't have a Palette included already, but that's simple to implement using the same DataTemplates as your main diagram.

Try the sample application for Silverlight 4 and VS2010 at:
GoSilverlightBasic.zip