RE: How should I....?
I knew a guy that did a 1/3 acre plot with a walk-behind tiller. It can be done but plan on a day. You will still need a spreader for fertilizer and lime, and some sort of drag to lightly cover the seed. A half acre is going to cost $25-$75 seed, $100 lime, $50 fertilzer. If you already had all the equipment its still going to cost you a couple hundred bucks.
I like a mix of clover and chicory in the fall. Oats are cheap and easy andthe deer love them through winter here(NC). For a spring plot tryiron clay peas mixed with lab lab. Or, you can find a old bush type soybean(like laredo) that can take grazing pretty well. My spring favorite is corn, but it is expensive to raise and a half acre probably isnt big enough to try it.