T.C.
What are you planning to use for the walls of the raised bed? I have seen concrete blocks, wood, and plastic edging. While you are thinking about how to build the raised bed you could plant a few things in containers, maybe starting with 3 tomato plants and 2 peppers. The garden center will probably sell them in the 4 inch size, and you could transplant them right away to bigger bucket-sized pots . Then you can set the pots in the garden to help plan the layout. The tomatoes and peppers always get bigger than I thought they would, so I try to plant small things in between, such as onions, radishes, spinach, cilantro, carrots, or marigolds(I heard they're supposed to repel bugs).