I currently have two post types, Posts and Tutorials. Tutorials are grouped into sets of tutorials within Courses, which I have created with a custom Course taxonomy. Courses can belong to multiple categories, as can Posts. These categories have been created using the built-in category taxonomy. Posts will never belong to a course and should have no association to them.
How can I set up this hierarchy, primarily the linking of a custom Course taxonomy to the built-in Category taxonomy?