Brandy:
I have some more questions..
I have found information and also have seen mention of grinding cereal. Can anyone give me more information or personal experience with this?
Along with the information Pat gave, if you have a Flaker Mill you can crush most grains into flakes (doesn't work with corn, soy, garbanzo and other large beans/seeds/grains). It also will mill grain into a coarse/chopped mixture similar to the multi-grain cereals (5-grain, 7-grain, 11-grain, etc. - except you can choose the grain/s), as well as a coarse flour similar to farina/cream of wheat/rice.
I have a Marga Mulino Flaker Mill - http://www.kitchenkneads.com/index.php?module=store_listings&action=view_listing&listing=63 that I use for this type of milling.
If you use unrefined oat flakes, spelt flakes, rye flakes (often purchased at health food stores), you can quickly make them with a Flaker Mill. My Family Grain Mill also has a flaker attachment for it. Both flakes and coarse/chopped grains cook much faster into cereal than whole grains, especially if you incorporate an overnight soak method.
I also have a Corona Corn Mill which is best used for coarse grinding (I use it primarly for corn meal since it can't be milled in the Flaker Mill and my Whisper Mill only mills flour). It's adjustable so you can control how coarse it grinds.
It will cost only pennies to mill your own multi-grain cereal, farina, and corn meal. Especially rice, which is inexpensive until you start looking at the more processed foods like cream of rice cereal and rice flour.
Edited to add: I get organic oat groats from Heartland Mill (www.heartlandmill.com/) 25# - $15.36, 50# - $28.25. Shipping grains is expensive. I'll pick up grains from this mill when I'm out in western Kansas for another reason.
~Gingerbread