combining small grains

We sell some of the seed, keep enough seed for ourselves, feed the cows with it, and we bale up some of the straw and sell it in the fall. The rest get chopped for bedding. All in all, I think the cost is offset enough to validate the means. Heck if we sell 75 bales, that'll be $225, unless we raise the price this year, which I think we will...
Donovan from Wisconsin

The combine's operator's manual is typically pretty darn thorough on settings, at least for the more common crops.

Ray Stueckle was a traveling combine expert, about 20 or 30 years ago, who had lots of ideas, some of which were at odds with conventional wisdom. He wrote a book on his ideas, gleaned first-hand over a lifetime working with combines, "Combine Settings For Better Harvesting". There are folk who dispute many of his ideas, but in any case, it's a good read.

He has passed, but his company is still around, R&H Machine. They list the book on their website as "sold out".

Link

Perhaps an internet search would turn up a used copy for sale.