I have laid black plastic over sod in preparation for a new bed. The grass looks dead. If I work this sod and roots into the soil will I have a weed problem later? The sod is mostly bermuda grass.[/b]

Yes. You will have a nightmare from now on if you till that stuff in to the ground. Best thing to do is get a sod cutter or somehow remove (without pushing any of the rhizomes deeper into the ground) the top 2" of soil.

Another thing you could try is to get a product called Sythe. Mix several ounces of it along with an equal amount of orange oil to a gallon of the 10% vinegar. Spray it on that which you want to kill. Someone has had success with this method as well.