Bring your favorite dish, appetizer, main dish or casserole and join us, family and friends for an afternoon of fun and fellowship. Come on over around Noon and plan to stay till seven or eight, bring your appetite and your good cheer as we visit and talk about the year.
It should include the date, start time, address, and reason for the party! It should also tell the invitee what to bring. If you're really organized, you'll assign types of dishes to the invitees this way you'll better ensure that you don't get all dessert dishes!
Apart from invitation date,time,location,guests information, the potluck party should have potluck menu. I found one website which has invitation+Potluck menu, where guest can select a potluck item for the party.