I plan on using the room next to me. I teach in a computer lab. And there is not a lot of room to move around in there (to form groups).
The room next to me is empty. So I plan on setting up table groups of 4. We will then use this room for discussions. I think my current plan is to just use different signs on the door to indicate what room we are meeting in (on a given day).
On day 1 we will also set up our classroom norms for discussions.