How do you conduct a "Focus Group"?

I want to promote a project in a certain community. The project will ultimately need the approval of the community. I want to measure public sentiment (for or against) before I get too far into the weeds by using a focus group. It's my understanding that there are consulting companies that do this - from qualifying participants to ensure a representative sample of the community, as well as making sure each participant has the intellect to fully understand the proposal. How do I approach this?

T.I.A.