The Salt Lake Tribune has this good article about how to plan your garden. Here’s an excerpt:

“List your plants from largest to smallest and then draw them, to scale, on your garden map. As a general rule of thumb, you will want to place the tallest, widest plants at the northernmost end of your garden bed, and the smallest, squattest plants at the southernmost end. This way, the tall plants won’t shade the small plants as the sun makes its way across the sky.”