Always try and use the phone # that you will be most often available to answer. Try and avoid routing calls to attorneys or other points of contact when you can avoid it. If you have a cell phone, use this on your sign and MLS listing. (and phone forwarding if you select this feature) The problem with making your attorney your point of contact is that this individual will most likely not be available on weekends and evenings. (when many showing request take place)
Also, try to avoid putting too many phone #’s on your listing. Ideally, have one phone dedicated solely to selling your property. Thus, when you hear this ring, you know to put down what you are doing and address the call.