Very glad you found us, too! Happy to help on this.
Yes, users must register, with the same group you used (group must be identical to work).
On your dashboard, until your account and a document are assigned to the same class, you won’t see anything in your document widget except under your “Created” documents if any.
Users and documents can both be assigned to classes, by editing the user or document in question, and adding the group value to it. Users can edit their own accounts, but not others’ accounts. Documents can be edited by their owners only, by clicking edit from the list at /documents.
Note that in all cases, there’s a somewhat unintuitive requirement, which is that you must hit the enter key on the keyboard before saving/updating the user or document.
I hope that gets you started. Let us know if you have further questions!