We met about every other week. I led off on the discussion or another volunteer teacher. The truth is that the discussions happened everywhere. People who hadn't volunteered for the group, begged for it. And I gave them copies too.
People learn in different ways, have different time constraints etc.
I find that offering choice is powerful. I now have lots more middle school examples and stories but at the time Mosaic came out, I hadn't done a lot in middle school. I would be honored to join you for one of your discussions and add comments etc. I'm very excited about your discussion and hope it turns out to be very useful.