Quarter the squirrel until you have:2 front legs, 2 hind legs, and the "backstrap" section. I usually throw the ribs away.
Put'em in a pot with some onions, salt, and pepper and boil'em until there tender. Afterwards, let them cool, roll'em in some some seasoned flour and fry the pieces untill golden brown in a cast iron skillet with a little oil.
Thats how my grandmother always fixed'em for me, imo they are not quite as good rabbits or quail fixed the same way, but their decent.
My uncle used to boil'em, then when done, pull the meat off the bones and use the meat with a can of chicken broth and some added water to make squirrel dumplings.