Hi Mêkāwý,

In my opinion, I think you should create groups on Facebook and Skype. Skype is more convenient for people to practice speaking skills. 

However, when someone need help or others share documents, it's easily be washed away and impossible to find again. Facebook group can fix these problems. It's also simpler to administer participants, and wipe out what's not relevant to learning issues.

I hope my sharing can give you some ideas. I'm looking forward to joining in your group.