The environment is so important to the sustained believability and success of a community. It must be set up to support what we value, both for ease as well as for alignment of message and practice. Consider the aesthetics of the room; use surfaces to convey the messages you want to convey, broadly in terms of reiterating and reinforcing rules and expectations visually, and specifically in terms of labeling locations in the room/world like points on a map. Involve students in the process!
Student seating in my room is done with two sets of two columns of desks facing each other. This makes it easy for students to work in pairs and well as groups of three or four. I already refer to students sitting next to each other as neighbors, so it will be quite an easy jump to refer to clusters of students, or neighbors, as a neighborhood. When I want students to mix up their groupings we can talk about "traveling to the next neighborhood." No matter what your desk situation is, I recommend that you try to configure it as much as possible for paired and small group interaction, emphasizing the community feeling however you can.
See Activity B: Centers with a Twist.