It sounds like you may be too experienced for basic books on marketing.

You may have already looked into this, but I would recommend looking into the Ag. and Extension services of the University of Illinois.

The University of Illinois Ag. website is http://www.farmdoc.illinois.edu/.

Iowa State University Ag. and Extension service also has good materials for the ag. community (sorry I don't have a link right now).

Finally, even though the CME does not seem to know what is are doing on a day to day basis, they do have some decent free educational materials.

http://www.cmegroup.com/trading/agricultural/grain-and-oilseed/corn_learn_more_education.html

http://www.cmegroup.com/trading/agricultural/files/AC-216_HedgersGuideNewBoilerplate.pdf