1. Try selling them online on something such as EBay;
2. Contact local callers and offer to sell them;
3. Donate them to a local caller's assocation.

Most of the records probably aren't worth much, except perhaps as historical interest. Modern square dance music has better recording quality and is preferred by most callers. Old record collections also tend to accumulate a lot of dust and scratches, and are generally useless, unless they are digitized and cleaned up (noise reduction). As such, I would venture to say that most of your records are only worth about 10 cents to a dollar, with an average of 25 cents or so. Occasionally, of course, there's an old out-of-print record that may be worth $10 or $20 to the right caller.

Donating them to a local caller's association might be the right thing to do.

We are documenting square dance music on our online 'Record Database', and, as such, would be interested in obtaining copies of any records that we don't currently have. If you have time, please look at our record database, perhaps searching by record label via http://www.ceder.net/recorddb/query_label.php and reserve some of the ones that we don't have. We aren't willing to pay too much for them, but we'd love to have them.