What are good areas to live in Toronto?

My parents and I live in a small city, and we like to move to Toronto. I've been told that Jane, Finch, Cabbagetown, certain areas of Downtown/ Yonge street aren't good areas. Are there other areas to stay away from? Does anyone know what are good areas? Is Richmond Hill a good area? I don't know too much about Toronto, in regards to what are good areas. The more information the better.