The basics
Peace lilies like bright, indirect light. A spot near a window without direct afternoon sun is perfect. They can handle lower light, but they may bloom less. Too much direct sun can scorch the leaves.
Water when the top inch of soil is dry, usually about once a week. Peace lilies droop dramatically when thirsty, then perk up within hours of watering. That makes them easy to read. Do not let the pot sit in standing water.
Wipe dust off the leaves now and then, and repot every year or two if roots crowd the pot. One note: peace lilies are not true lilies, but the ASPCA lists them as toxic to cats and dogs if chewed. Keep them out of reach of pets. See the ASPCA list (opens in a new tab).