Lee,
I had 64 sq. ft. of garden. As far as design, use interplanting of edible flowers like Viola. Shorter plants around the outside, taller plants in back towards house, and medium plants around taller plants. Mix in swiss chard, mums, and other edibles that are also used as ornamentals.
Flowers draw the eye away from the green. You want to guide the visitor towards the front door of your house, or path, the garden should be background rather than a main feature. You could even include a water feature near ends.
Use a raised bed, edging, clean boarder, with mulch or grass paths. I had an "L" shaped bed and grass would get mushed around inner corner. Would have been better to put a stone steps around the bed -- something you can mow right up over.
You'll want your grass cut weekly in the growing season, seed it with the four or so best seed in your area.
Polyculture your grass so you'll have greenish yard all year around since most people don't understand the grass goes dormant.
If you chop and drop vegetables as you harvest then mulch over it in bare areas. Or collect cuttings to
compost and return as uniform compost. My HOA had rule about "no bare soil" wasn't an issue with plants year around with good mulch.
In my backyard I have 6 foot tall
trellis with long beans, can't do that in the front yard. You likely don't want any structures in the front yard outside the beds. Lots a good
books on landscaping, just substitute edible plants that look similar.
My lot at the townhouse was under 800 sq. ft. front and back. Some of my Spring 2012 photos are on my Flickr account at
http://www.flickr.com/photos/hittjw/sets/72157630192372960/ plus what is linked above. Don't mind the powdery mildew on squash in the middle.
Best,
Justin