I have a 6 year rotation on my garden. Plot 1 is brassica/onions in the upper half, grains and oilseeds in the lower. Plot 2 is greens/roots, Plot 3 peas/dry beans/misc legumes, Plot 4 is okra/corn/snap beans, Plot 5 if squash/cuke/melon/watermelon, Plot 6 is tomato/pepper/eggplant.
I use a six hour rotation on FarmVille.
We just try to not plant the same thing in a bed two times in a row.