yea!!! I decided to do square foot gardening too this year. make sure to do research on what plants do well near others and planting according to the direction of the sun to the plants height.
If you're going to grow tomatoes make sure to grow the kinds that grow like vines instead of bushy and short. You can fit a vine tomato in a single square foot, but bushy ones need @ least a couple feet space. You can fit tons of radishes(16),carrots(16), beets(9), bunching onion(16) & sugar snaps (9) into a single square foot.
If you're going to plant some greens (lettuce,kale,endive...exc.) you can put 4 into 1 square foot as long as you keep harvesting the outer leaves once they start crowding together.