Pick the spot
Vegetables need six to eight hours of direct sun. Watch the yard for a full day before you dig, and note where the shade from the house, the fence and the big tree falls in the morning and the afternoon. A bed close to the kitchen door gets checked more often, which matters more than most beginners expect.
Test the soil
A cheap test kit tells you more than any amount of guessing. Take samples from three or four places in the bed, mix them, and test the mix. Do it in early spring so there is time to correct the soil before planting.
Check the pH
Most vegetables grow best between 6.0 and 7.0. Lime raises the pH and sulfur lowers it, but both work slowly, so add them weeks before planting and test again.
Check the drainage
Dig a hole a foot deep, fill it with water and time how long it takes to drain. More than four hours means heavy clay, and a raised bed will save you a season of rotten roots.
Choose what to grow
Start with five or six crops you already eat every week. Lettuce, radishes and bush beans grow fast and forgive mistakes. Tomatoes and peppers take longer but pay back the effort. Leave melons and corn for the second year, when you know how much space you really have.
Build the beds
Raised beds four feet wide let you reach the middle from either side without stepping on the soil. Twelve inches of depth is enough for almost everything. Fill them with a mix of topsoil and compost, and leave a path wide enough for a wheelbarrow.
Wood or metal?
Untreated cedar lasts eight to ten years and stays cool. Galvanized steel lasts longer and warms up faster in spring, which helps in short seasons.