Well, the best white egg layers are White Leghorns and Leghorn crosses, which are light birds but tend to be flighty and loud. There are several good brown-egg layers like Rhode Island Reds and RIR crosses, Black Australorps, and Barred Plymouth Rocks. These are heavier dual purpose birds and tend to be more docile and quiet, but take more space per bird. Alot of folks do that. I'd use at least 6 ft. high chicken wire to section it off.
All chicken eggs are good to eat.
If the eggs are soiled, you can wash them in warm soapy water, otherwise, there's no need. Otherwise, they will take a break from laying during the winter, too. The heavier breeds lay best through the winter if it gets pretty cold where you live. Most people don't bathe their birds unless they are getting ready to take them to a poultry show. Chickens will stay pretty clean if you keep a deep layer of shavings in their coop which you stir up often and completely replace when it needs it.