There are several books available on the subject: Edible Estates: Attack on the Front Lawn, Edible Landscaping, The Edible Garden.
There are websites dedicated to the concept: Designing Edible Gardens, How to Design an Edible Garden, Edible Landscaping, Edible Gardens from Gardenguides.com, Save Money with Your Edible Garden.
You can use herbs as food and as decorative elements: Growing Herbs As Decorative Plants, How to Plant a Decorative Herb Garden.
And you can also make a lush container garden if you have limited space.