Book Fairs

I have been thinking about doing some book fairs next summer. Some of my writer friends have done them and had good times as well as selling quite a few books at them. The only thing you really need to set up a booth at those places is either one or two nice portable folding conference tables or even just one folding card table. Some shade is nice for the outdoors ones, but if you stick to indoor ones you don't even need that. A comfy folding chair and you're all set to spend the day talking with people about books. There are several high profile book fairs in the Chicago area each year. That would be a nice 'day out' for me without having to travel far. Have any of you been to a book fair in your area? What did you think of them? I'd love to hear any feed back about what you thought of the whole thing, what things you liked to see at the booths if there were little extras and such. I'm open to all advice on what would make my 'space' nicer.