One was a link where a person had mirrored my course...

Taking your content, and placing it on their servers for display without your permission is not a very polite thing to do. You would be completely justified in asking them to take it down and replace it with a link to your site.

Nowhere does it list how people may or may not link to it.

I haven't heard of a single country in which people need your permission to link to a website. Links that misrepresent the course (e.g. click here for the course cjf wrote ;) may be another matter.

Are their any legal issues that I should be worried about?

I would ask anyone mirroring your course to replace their mirror with a link. Suggest this is because you want to ensure the content is up to date and they'll likely agree. I wouldn't worry about who's linking to your site though, it's not something you can really control, and I'm not sure why you would want to.

Update: As for a notice of copyright this says:

The use of a copyright notice is no longer required under U.S. law, although it is often beneficial. Because prior law did contain such a requirement, however, the use of notice is still relevant to the copyright status of older works.

And a few more relevant links:

• Copyright.gov Faq
• Copyright Basics
• What works are protected?

Hope that helps :).