The first year I ran the bookclub, we'd just come to a consensus about which book we were going to read. Whoever had an idea would bring it, describe the book a bit, make a case for their choice, and then we'd vote. But last year we decided to start taking turns choosing the book. It turned out to be a little more fair, as under the old system the more vocal members ended up choosing most of the books.
I've been in charge of my book club since its inception, but have just handed over the reins to someone else -- she'll be running her first meeting in January. The way I did it was just to sort of go around the room and let everyone have a brief (sometimes not so brief) say about what they thought of the book. I usually tried to come prepared with some good discussions questions as well. You can often find those on the internet -- either on the site of the book's publisher, on Amazon, or on various book-y web sites. So after every had their say, I'd throw a few questions out there and just let the discussion run its own course. Sometimes people have a lot to say, other times it's a bit quieter. It depends on the book (and how much wine the hostess for the night has supplied!).
The most challenging thing is keeping people on topic. With 12 tipsy women all vying for the floor and talking at the same time, you sometimes have to be quite firm in getting people back on track and focusing on the book, rather than on village gossip, what they watched on television last night, etc. I often wished I'd had a gavel!
There's another book club in our village, and they seem to run their meetings a bit more formally. They have an "assignment" each month, which is in some way connected to the book they're reading. For instance, they might have to each bring and read a poem or passage that is on a similar subject. I actually wouldn't mind introducing that into my book club, but the other members prefer it to be more relaxed.
Are you thinking of starting a club, Stacey?