Well, I can't help you permit wise, but I know there is a big difference between going door to door with the usual 'we have extra eggs, would you like to buy some?' And actually running a business. You might get in touch with your local grocer and see if he would consider stocking your product. For best results, ask a mom-and-pop store, because big businesses need to have a minimum order that is way higher than normal farmers can manage. Do you have special eggs? Tell about it! Whether it be color, or the way the hens are raised, or fed. Do research on what it takes to get your flock certified by the health inspectors. Here in America, we call it USDA. Be very careful when putting things like 'natural' and 'free range' on the boxes, because they have official definitions that may vary from the common use.