The first thing to when considering a vegetable is a little planning. Choose the garden location carefully. Find a sunny spot, vegetables require at least 6 hours of sunlight each day (though more is better) to warm the soil and provide the energy necessary for good plant health. Selectively prune some of trees in the vicinity to allow some extra light into the garden. Locate the garden near a water supply as well, this is especially important. Think about how much time you're willing to spend in the garden, this will help you determine the size garden you should plant. Be sure to plant vegetable varieties which do well in your area and check all seed packets for expiration dates. Start with a modest selection of plant varieties, avoid vegetables which traditionally have the biggest disease and insect problems.
Vegetables will survive in poor quality soils but for best results amend the soil. Vegetable gardens prefer soils rich in nutrients so prepare the bed as you would any garden bed. Till the soil and add compost, peat moss, and manure to enrich the soil. Apply lime to garden in either spring or fall. A fall application will give the lime time to react with the soil before the next planting. Apply fertilize in the spring and work into the soil. If you have a compost pile top-dress the garden at any time during the season to freshen the soil and add nutrients. If you don't have a compost pile, start one. Vegetable plants are great for compost piles as the decompose quickly. Starting a pile also gives you a place for all your other yard waste. Rotate your crops each year.
Draw out a plan for your garden and make a list of plants you'll be using. Plan for a continuous harvest. Plant crops which will be ready at different time of the season. A few different varieties any at time. Its best to have a modest selection throughout the year rather than too much at any one time.
Building raised beds can extend the growing season since the soil is able warm up sooner than the rest of the garden. They also offer better drainage and deep topsoil with little compaction. If you add compost to your garden each year a raised bed may occur naturally. If your garden tends to get water logged building one is probably a good idea. You can use a variety of materials such as landscape timbers or stone. Raised beds are easier to tend to as well, they are somewhat protected from the encroaching grass and weeds of its surrounding environment.
As for planting the beds orientation should be considered. A north to south row will receive morning light on end and afternoon sunlight on the other. This situation is suited to low growing vegetables. East to west favors taller plants.