The Mineral Help tab above is a useful place to start.
Also get familiar with the Oklahoma Corporation Commission website. They have useful publications for the mineral owner. Their website is free. Here are some handy sites that I use.
Pending OCC cases at the following link: http://www.occeweb.com/caseprocessingonline/default.aspx
Actual cases if you have the case numbers: http://imaging.occeweb.com/imaging/OAP.aspx
Docket proceedings: http://www.occeweb.com/ap/docket_results.html Well activity: http://imaging.occeweb.com/imaging/OGWellRecords.aspx
Production: Gross Production
The National Association of Royalty Owners has an Oklahoma Chapter. Their mission is to help mineral owners understand what they have, what their rights are and to teach folks how to handle and steward their minerals.