Intermission - Movie furniture

I'm not really certain where film makers get the furnishings for the various sets. In The Messengers, the furniture was quaint and found in the home by the new inhabitants. In War of the Worlds, there was a mix of furnishings in Tom Cruise's house in the city, yet very elegant furniture in his ex-wife's house in Boston.

Do movie makers buy new furnishings from places like Century furniture, or do they scour estate sales or local shops for furniture? Of course, maybe I'm crazy for even wondering, but I actually do look at how rooms are arranged in movies and the accessories they've placed in them.