When I have neighbors wanting to try VOIP, I set them up with a free NYC number through CallCentric or a paid number through
Voip.Ms.
We test to make sure they feel comfortable with whichever service and features.
If they have forwarding on their existing service they can forward to the Voip number to test inbound calls.
Once they are happy they can either buy a number in their own area code or port their existing number to the service.
While GoogleVoice is free, you may notice that most of the messages here in the forum are GoogleVoice-related issues. GoogleVoice has many pros and cons in my opinion.