Excellent advice from Rick, and I would just add -- do everything you can to get rid of the grass and weeds* that will plague you forevermore otherwise. In particular, don't let any go to seed... there's a saying that goes something like "one year's seeds, 7 year's weeds." Which refers to the fact that those weed seeds can stay dormant for a LONG time in the soil.
*short of using any kind of herbicide that will stay in the soil, of course; not very conducive to growing a garden! Which just reminded me of the time my elderly FIL mistakenly used "Weed & Feed" to fertilize his little garden...
