Pardon the commercial interruption. I found this nice little tool in the Gardner's Supply website. I like it because it lays out how many of each plant I can put in each square foot. While the plant selection is limited, I can extrapolate to related plants and to the actual size of my raised beds.
Gardner's Supply Planning Tool
"The only thing I have to eat is Yoo-hoo and Cocoa puffs so if you want anything else, you have to bring it with you."