Don't rush in...
Put your users at the core of your build: It is essential to take the time to fully ascertain the requirements of your community and what tools might be most appropriate to meet their needs. If you rush it and bang up some discussion forums overnight you may miss the point.
Don't underestimate the resource impact...
...particularly in the early, formative stages of building a community. It takes a lot of love and dedication, but mostly hard graft, to get a community up and running and to keep your users engaged and retained.
Do have clear and unambiguous moderation policies in place
You will inevitably have thorny issues to deal with right from the off; you need to have a robust framework of rules and procedures in place so that your users feel that you are providing a safe and consistently managed space. That said, you neednít be too draconian!
Do get stuck in to driving the community yourself through your own interaction...
...but be sure to keep a professional distance; itís all too easy to get sucked in to the emotional tumble-dryer and start taking things far too personally!
Identify problem users early on and work out a strategy of how to deal with them
If they get rooted in they will become more not less problematic. Again have clear policies in place and take a judgment call on whether you should weed them out sooner rather than later.
New Media Manager at Breast Cancer Care