Gardening

I want to plant things outside this year, have them grow, and then eat them. I'm willing to invest quite some effort in the planting and the eating, but as I can't be relied upon to remember their existence in between, something tough is probably advisable. I'll be planting in window-box sized things, since there's a lawn and flowerbeds out back that the landlady probably won't want us to dig up. Assume I know absolutely nothing about plants (which isn't too far from the truth).

So, what can I grow? All advice gratefully accepted.