I'd say the hardest part is finding an appropriate room. I think it's best to have a room that seats around 20 - 30 people with good acoustics. The general public should hear what's going on so best not out of the way.

Almost as important is a nucleus of support singers or tune players who will definitely come to the first session. If that goes well you ahve a chance. In this day & age e-mail can do wonders.

Best of luck

L in C