Just to make sure I understand well,
All viewport related event handling including selecting objects, points, keyboard strokes etc. can be found in RhinoCommon. And events that refers to the plugin user interface for example: click on button etc. is in the .Net c# documents namely under the Winform or other ui libraries.
So, for example if I want Rhino to act after a double click I need to find resources in the Rhino Common and not under MS c# documentation.