Laurel Snyder has a great split personality post over at About.com's Fiction Writing Channel on how to subit to an anthology, interspersed with advice on editing one. She is the editor of Half/Life: Jew-ish Tales from Interfaith Homes.
My favorite piece of advice: Submit to an anthology that attracts a different demographic than your own. So if you're a guy, look for an anthology on love stories or postpartum depression. They're looking for a variety of different perspectives, and your story will stand out.