Like Joe Offer says above, starting with a core group helps. That's what we did here in Yellowknife. We sing in a circle and take turns. Some people pass, but most have something to contribute. We try to discourage people from requesting songs of others in the group, unless it's an all-together chorus number.

The "Rise Up Singing" book by Sing Out! is so well used at our ceilidhs that we refer to it reverently as "The Bible".

Good luck, and remember to have fun!

Moira