Art Appraisals

My wife and I have inherited some pieces of wall hanging art from our parents and are not interested in keeping all of them. They include prints and paintings and we know a few of them are from fairly well-known artists. We would like to have them appraised with the idea of perhaps selling some of them. As we have no idea whom to contact we would be very grateful if anyone has been faced with a similar situation and found some one or some company who or which can provide an approximate value to these items. Thanks.