I have collected antiques since I was 12. By the time I was 14, I had a Victrola and I would buy lots of 78's, many of them Classical, Opera, Swing, etc. I would wind it up and play records constantly. One of my biggest memories was every time it was meeting night, I would get ready listening either to old classical 78's, or some of Judge Rutherfords talks on 78's that I also had collected that were used for service during the 30's and 40's.
There is a record value guide that you can buy that will show you the rarer records, but a quick check on Ebay will show you the values with a better idea of what someone will pay.