Will,
thanks for your advice. I'm someone with no prior experience and who has small children at home and a busy job, so reading your link and post is a little bit intimidating. But I do have a goal to produce 10% of the food my family consumes by two years from now so I'm realizing there's a lot to it. I expect a lot of failure in the first year but hope to learn and do better in year two. I live in southern ohio, 40 to 45" of rain in a typical year, good soil, zone 6. I plan to can and freeze food to attain this goal. I live right in town, just outside of downtown so having animals is not possible, at least not yet. If I get my garden up to the 1000 to 2000 sq ft range and have a couple fruit trees and a couple berry bushes, is 10% a realistic goal for a family of four?

2000 sq ft? You might well be able to hit 90-100% with that eventually, assuming you like potatoes, vegetables, fruit and beans. 10% in two years sounds eminently reasonable to me.

My little Zone 9 or 10 porch, well, that likely won't hit 10% unless I work really hard at it. This summer I managed a whole two radishes, so I've a long way to go.