OK, the thing you thought was never possible has just happened: Not only are people visiting your community, they're visiting it in droves! Every time you look at your community, there are 10 more messages waiting to be answered, three more newcomers to greet, and two old topics to archive.
Great! You're a success! Now, how are you possibly going to handle all this success by yourself?
You don't have to. You can bring on a community host to help you manage the community. So how do you identify a great host? Here are some pointers:
A community host has to be able to deal with anyone who enters the community, without creating flare-up and problems. Communities are emotionally demanding, and thus require a calm, firm, gentle hand and a mixture of warmth and resiliency. If you imagine that you have to leave this person alone with your children, you'll have a pretty good handle on the set of characteristics you're looking for. This is probably the most important trait, and one at which people are notoriously bad at self-assessing.
A community host has to have both a strong nurturing ability and the wisdom to know when to stop nurturing and hand control over to the leaders who arise within the community. The host needs these qualities because a successful community will require lots of personal attention at the start, and will eventually become too big to manage. What you want to avoid is someone who manages every detail of a project: These people will not surrender control gracefully, and will eventually crush the life out of the community. Instead, you want someone who can oversee lots of different things, without feeling the need to directly control any of it. When talking to candidates' references, you might probe about how they managed projects in the past.
A community host has to be interested in new ideas, receptive to different opinions, and able to help organize information in a way that promotes new learning. This will allow the community to grow in ideas. Flexibility in thinking -- along with active seeking of new ideas and knowledge -- is imperative. Also, an ability to organize materials is helpful.
A community host has to have a good handle on the subject area. A host who has gone through the same experiences as the members is more likely to be able to guide a discussion.
A community host has to be able to think out loud in writing. You're looking for a certain openness with information and knowledge, and a lack of fear about looking foolish when thinking out loud.