Leasing in Western Zavala County

I am looking to help a friend who believes he owns minerals in western Zavala County. Assuming he is correct.....and someone approaches with a lease offer.....what are the current terms for Oil and Gas leasing in the area. I am a Landman....and I would assume that the standard lease offer is for a 3-year paid up lease, with possible extension language for an additional couple of years. Is this correct? In addition, what is a reasonable (not greedy) expectation of bonus and royalty figures for leases in the area?