HouseConcerts.com (description)

House concerts are small, intimate concerts held in the host’s home or an equally tiny venue. HouseConcerts.com has created a listing of people all across the United States and Canada who welcome performers and small audiences into their homes.

You can search through venue listings that detail locations, how much the rooms cost to rent, and how many people each will fit. HouseConcerts.com even has a booklet available by mail order on how to host your own concerts. If you are interested in performing alongside other artists, there is also a list of singer/songwriters who frequently play house shows.