If you decide to build raised beds, there are several option. You can either till up the area and then build your beds, or you can lay down several layers of newspaper to cover the existing vegetation and bring in soil to build the beds. Your decision will depend somewhat on what is presently growing on the location and how hard you want to work. I like to get most of the perennial roots out before I start planting on top. Now is also the time to add amendments such as compost, manure, etc. You also must decide if you are going to enclose the bed with boards or something to keep the soil in place. The beds should be at the least raised 6″ and up to 12″. Six inches is not enough if you are not digging into the ground. Most vegetable plants have roots that go down further than 6″.
To build your raised beds, use stakes and string to square the area and define each bed. I like to make the paths wide enough to run a wheelbarrow and a push mower between the beds. If you are digging into the soil, rather than the newspaper/add soil method, begin with a shovel and dig out the paths, throwing the soil into the raised bed area. Try not to step on the raised bed area, as that will compact the area. Seeds, plants grow better in loose soil. Use a garden rake to shape your beds. With the tines down, you will move alot of soil. With the tines up, and the top of the rake down, you will smooth the soil and shape the bed. Our beds are enclosed in two 6″ boards, so they are 10-12″ deep. You can make the beds as long as you want. I like them 10-12 feet long. Many people make them only 4 feet long. We used pressure treated wood. To hold the boards in place, we have used wooden stakes, but they rot in a few seasons. WE have settled on 2 inch angle iron on the corners and 1 inch angle iron on the sides of the beds.