Are there any good examples of Moodle use I can see?

Try the Mount Orange School demo, a working demonstration site full of examples for you to see and play with or Royal Roads Open Educational Resources.

How do I share ideas and learn from other educators using Moodle?

By participating in many ways, either through events, Moodle Community Forums and networks elsewhere.  You can find and share courses and activities on our Moodle Community hub. You can download courses to use in your own site and publish course content to share with others.  Within your own Moodle site, you can share courses with colleagues by using the Course import or Restore features.

Are there any good sources for shared courses?

There certainly are.  Via Community Hubs you can search for, enrol in, download and publish, and share courses.