I haven't yet read Barbara Kingsolver's Animal, Vegetable, Miracle in which she and her family spend a year eating only (or mostly) locally grown, seasonal food. To attempt this discipline would be a worthy goal; and, for folks like us with a farm, should certainly be achievable. Clifford and Louise who lived here before us, ate mostly local seasonal fare -- but they ate beans and corn and potatoes, day after day with only small seasonal variations. ( They were fond of bananas for banana pudding but I could give the bananas a miss if I could still have olive oil and coffee.)
We've been spoiled by relatively cheap, out of season food -- asparagus from Chile, strawberries year round from all over, shrimp from Thailand. But the cheap part of the equation is rapidly disappearing and we're beginning to think about changes.
My husband recommends two books by Michael Pollan -- The Omnivore's Dilemma and In Defense of Food. I haven't read either yet but am charmed by Pollan's simple suggestion:
EAT FOOD, NOT TOO MUCH, MOSTLY PLANTS.
Sounds like a plan.