Information needed Section25-8N-5W Grady County, Oklahoma

My husband and I received an inquiry from a Landman to lease our mineral rights in Section25-8N-5W, Grady County. We were unaware of these mineral rights and they appear to be part of an old Family Trust. Does anyone know what is going on in this Section? Also, since we are unfamiliar with the laws in Oklahoma, can anyone suggest how to research a Family Trust to find out what other mineral rights might be in it and how to determine if this is a good Lease Agreement? Do we need to contact a Lawyer to have him review the document - or does a Landman review it. We live in Florida and this is all new to us. Any help will be greatly appreciated.