The best degree program is Energy Management or Petroleum Land Management (same thing, different name). There are about half a dozen colleges in the U.S. that offer this degree or a variation on it. Oklahoma, Mississippi, Lousiana, Texas, Texas Tech, Houston, and Tulsa offer these or similar degrees. Of these, Texas Tech's and Lousiana's are very solid and Oklahoma's is the oldest and generally considered the best. Tulsa is starting a new program that will quickly rival OU's given Tulsa's established reputation as a top-notch petroleum engineering and oil & gas law school and an excellent director.
The program is basically a business degree, but it's somewhat interdisciplinary. It's heavy in finance, legal studies, and accounting with some geology, basic engineering, and energy seminar courses thrown in. Also, many landmen don't have an EM/PLM degree or a law degree, it's possible to get into landwork with any degree if you know someone.