I suggest to all of you eyeing your lawn to put a raised bed over the grass instead of digging in. It is much easier.
Steps: 1) mark off area to be your future garden 2) frame off outline with wood boards 3) layer the bottom with a think layer ( 1" or so) of old newspapers or cardboard making sure to over lap. This will kill the grass and there will be no need to dig it up. 4) fill with soil and compost 5) plant!!