This all depends on your soil. If you have heavy clay soil, you will either need a large tractor (farming) if you want to go big (several acres) or you can go small (plots 1000-3000 sq ft) with even a garden tiller. If you have light soil, you can probably work it up pull-behind tools and an ATV or heavy duty lawn tractor. Sounds like you have heavy soil.
Small pull-behind tools and a garden tractor and ATV won't get far on heavy clay soil although a pull-behind disk and ATV can break up and level heavy soil after it has been plowed or bull-disced by a farming tractor. Perhaps rent or borrow a bull disk for your brother's tractor. Ask around - some farmer may have an old plow they will sell.
I would start small and do it right. Work up a small plot and then get a soil sample and add fertilizer as recommended. Staying small allows you to afford all the fertilizer and lime you may need. If needed, protect your small plot if the deer are mowing it down. Where you are, you still have time for a variety of fall plots - see
http://www.aonmag.com/article.php?id=1853&cid=195 . See
http://www.deerhuntingbasics.com/foo...alculators.php for the basics of getting a soil sample, finding a testing center (costs only about $10), and figuring out how to add recommended rates of fertilizer. After you get a small plot established, perhaps work on additional plots in future years.
Another alternative would be to have a larger plot of perhaps 1/2 acre and within this plot do a small quality plot that is properly tested, fertilized, and limed.