Selling Eggs

If you are only selling / giving eggs to the people who are eating them, you have to simply follow sensible food safety.
But the moment you sell / give to anyone who is either using them for baking or cooking for somoeone else to buy; selling / giving them to someone who will sell them on; or in any other way breaking the direct food chain then you need to register as a packing station with Edinburgh egg and poultry unit.
Good food safety is to collect them daily, several times if very hot. To keep nestboxes very clean; not to wash eggs; to store them in trays somewhere that has a stable cool temperature.
You should not call them free range unless you are registered as it is a legal special marketing term. but Free Roaming is fine.
If you can take an elementary food safety certificate locally that is a great way to show you have the understanding and are prepared to fulfil the necessary due diligence to take care of your customers.
Class A eggs are again a specific term, and require particular grading and care.
Putting sizes on eggs requires accurate weighing scales.

these links are for Scotland, if you live elsewhere you need to find the appropriate department for your area.
Egg Inspections