Being stuck (very unwillingly) in suburgatory, I'm an avid raised bed gardener.
I started last year with two 4'x4' beds and two 3'x3' beds. This year, I added a 9'x4' for herbs and melons (which trellis themselves on the fence behind the bed), one more 4'x4', and a 4'x6' for corn.
Raised beds are awesome because you never, ever have to weed, they are easier to work in and around, you can grow tons more in a much smaller space, crop rotation is simple and insect pests minimal, etc. etc. I make my own soil mix out of 1/3 each of peat, compost, and vermiculite. My garden last year (and this, thus far) went absolutely nuts and was the marvel of the neighborhood.
My corn was several feet taller than my neighbor's and fruited earlier and more heavily. Same with everything else I grew. I'm a nut about growing everything organically and preferring heirlooms to other varietals. I had an amazing season.
Great info on maximizing yield, etc.:
http://www.squarefootgardening.com/
Enjoy!!