well the zucchini is going to totally take over, and you're going to start leaving it on people's porches in the middle of the night...you will do anything to get rid of it, because it will all be ready at the same time. Seriously, no one in the history of gardening has ever been able to not grow too much zucchini. So it's a good one to start with. And salad greens are great--it's such a treat to be able to just pick a few leaves to go with dinner. Peppers and tomatoes would be delicious and save you lots of money in the summer.
I love Square Foot Gardening. Right now my apartment is right over a major highway. When I saw that it had a fire escape, I immediately thought of all the things I could grow, but then realized that all the chemicals would concentrate in my poor little herbs and tomatoes. Sigh. Someday I'll have a garden again!
Il faut vivre et non pas seulement exister.