Washington Farmers Market, downtown on the square, Thursdays from 5:00 - 7:00, has fresh garden produce (local & brought in), homemade baked goods, salsa, & noodles, plant starts, divisions, and cut flowers, and sometimes live music. The salsa contest was last week.
There is a second market on Sunday afternoon - less well attended - to move the things that didn't sell on Thursday.
How many vendors? between 12 and 20, depending on the time of year. Someone writes a follow up article for the newspaper telling what goodies were offered.
Many of our vendors accept the food coupons that low income people can get for fresh produce purchases.
The market has been there for at least 5 or 6 years (probably longer), and some local farmers plant specifically for that purpose - things like various colors and flavors of peppers, white eggplant, tomatillos and such.
Hope this gives you some ideas to help your market grow.