Allibeth- we are in central NC and have heavy clay soil that is probably the same as yours. Study succession and if you have the funds or know someone who has the books "Edible Forest Gardening" by Dave Jacke, I would highly recommend them. While there is a lot of information out on the web, I found it very helpful to have a singular voice through the books to become grounded in the ecological principles at work.
Since you do not have many trees, consider moving from field to forest slowly. I would avoid planting any fruit trees or shrubs if your soil is as poor as ours was- little to no organic matter, hard packed, etc. Even if your nutrients are up, I would seriously wait another three years before investing in your food production. In the meantime, follow the advice of others and plant polycultures of soil building plants.
Brassicas, native nitrogen fixers (
here are some of the plants we ordered this year)- herbaceous, shrubs, and trees, root crops, etc. We are focusing on filling out our nectary calendar (diverse plantings for insects of all kinds, with blooms as long as possible) and restoring fertility. This takes a lot of the pressure to "produce" off of your shoulders while you heal yourself and the land. I say heal yourself because permaculture requires sacrificing a lot of the "common" knowledge/baggage we have learned about maintaining landscapes. As you observe through the first few years (we are on year two now), you'll become more comfortable with the idea of letting go and trusting in the way nature works.
Anyway, thats my 2c.