I use the University of Illinois forms for cash rent on one farm, for share rent on another farm.  I adapted them a bit to fit conditions, but they are very good forms prepared by the University.

A link to the cash rent forms is: http://www.farmdoc.uiuc.edu/pubs/Legal.asp?Subsect=Acquiring&Subclass=Lease

You can download them into Microsoft Word and save them, or use Adobe, there are links for both formats.

There is so much good information on the farmdoc website, I go there a lot and just browse what it contains.  There are fast forms for grain delivery and various quick calculations for many farm activities.  You can also find a good machinery rental schedule there.