the easiest way i found to weigh them without injury is to place them in a plastic Walmart bag. the fish usually don't flop around much in the bag and you don't have to worry about hanging them on the scales with the big hook.
Good idea, Scott! A hefty black plastic garbage bag might be even better for large bass. They can slip off too easily & injure themselves falling to the bottom of the boat, plus there is the danger of too much weight on their jaw. Black color good because fish, like most animals, tend to calm down when in darkness. Just make sure to put a little water in bag so they don't lose slime coat.