John,
Glad to hear you're interested in using Moodle's badges feature. I've played around with this for testing purposes within demo accounts, but I only have a little experience.
Here's the documentation on the feature from Moodle:
Does this help you understand how to get things working for your class? Badge sharing occurs when students connect badges to Mozilla Backpack accounts and create shared collections. They can then share those over email, social media, or on their personal or class websites.
Let us know if you have more involved questions, and we may be able to locate a Moodle veteran to help answer.
Nate Otto
Director, Badge Alliance