Your garden should be planned with the goal of providing a large assortment, as well as a continuous supply, of vegetables throughout the growing season.
The size of your garden will depend mostly on how much land you have available to you.
On a farm, or a large country property, where the garden's size is limited only by the gardener's desires, vegetables should be grown, not only to supply summer's wants, but also for winter storage.
On a typical, large-sized city lot, you likely have enough room to grow enough vegetables to supply you throughout the summer, but you may have to give up growing vegetables that have large space requirements, or to grow enough of any variety for winter storage.
On a small inner city lot, or on an apartment balcony, space is significantly limited, and the only vegetables you'll likely be able to grow are those that produce a lot of crop with minimal space requirements.
Regardless of where your garden is located, whether on a farm, a country property, an inner-city patio, or a downtown apartment balcony, the principles of planting and care of a vegetable garden remain the same, though things like planting distances, methods (or elimination) of tilling, and intensity of planting will each be unique to each individual garden.
On a farm, or on the large country garden, saving labor is often more important than saving space, and row-based planting is wiser than planting in beds.
Depending on the size of the garden, mechanical aids can be used in soil preparation.
In the typical home vegetable garden, however, vegetables are intensively planted as closely as their growth will permit, and almost all soil preparation, and garden maintenance, is done by hand.