If you are planning large raised beds, remember that you will have to hand dig all the grass runner roots out, constanty, every year. My 3x20 raised bed boards are giving out (linseed oil coated untreated, around 2" thick, after about 6? years. Expensive. I have perennials in the beds--roses, peonies--but if I were doing vegetables again, I'd stick with ground-level beds with permanent walking path areas, so I could roto-till. Unless your soil is bad or too wet, of course.