I remember watching the PBS program, "Square Foot Gardening" when I was a kid. Learning heaps then. Now, Mel Bartholomew has revised his book from the 80s, concentrating on companion planting, diversifying plant species, improving soil mixes for minimal watering and avoiding chemical usage (for pest or fertilizers).
Great idea for small spaces, for implementing a no-dig method, it minimizes weeding, and is easier on the back.