Generally, if you are selling food products anywhere other than your own property, you need a permit, business license, etc. from your state government and you have to follow their regulations. Food is already, and will be more so in the future, heavily regulated. To sell eggs, you need an egg handler permit. To sell canned goods or other "value added" products, you need a food handlers permit, etc.
To sell in a market you SHOULD have the above, although the policing of the farmer's markets probably varies by place. Health inspectors can and do show up to make sure everyone is following the rules. In addition, you have to have a table and sometimes you are required to have a canopy. You pay the market a % of your sales and also a flat fee for the space to put your table and canopy. You technically SHOULD also have liability insurance in case someone trips in your booth or gets sick from your product, so they cannot bankrupt you.
Many farmer's markets have contact info and sign up info on-line. Check out the rules . . . lots of markets stipulate that you need to set up early and stick it out all day, even if you sell out of product.
If there are no markets in your area, you might consider looking into farmer market associations . . . I think there are some organizations nationally and by states, and you would want to maybe form a committee of like minded people to get one rolling in your area. Good luck!
and will hopefully have next summer hatching eggs for sale from our chickies and duckies and perhaps some soaps and the like.
