To build a community you have to do the following:
- Determine a purpose or goal for it.
- Decide who your target audience will be.
- Design the site keeping in mind the tools for interaction and the structure of your community.
- Decide upon the manner in which you will host the community.
- Create the community using tools available.
- Create interesting content for the community.
- Invite or attract members to join your community.
- Administer it properly so that the community flourishes and expands.