Ask HN: I want to host a HN Meetup...

I live in a good area for HN meetups, but no one hosts them. Since I haven't been to one I don't know what they're like. The networking and potential for goood discussion interest me most. I was curious: what location are these things usually at? Bars? Event rooms? Do people give lectures or do they just mingle? What about food? What else should I keep in mind?