Crayfish, also known as crawfish, crawdads, or crabs, or soft shell crabs are the number one live bait to catch smallmouth bass in the river.You want to use smaller crayfish 1"to 1 1/2" hooking the crawdad up through the tail. Bass tend to shy away from larger crayfish due to their larger pinchers.
Shiner minnows are also good hook through both lips.The problem I have with minnows is that the perch will bite them but that's ok if your after perch.
Worms or nightcrawler are also great just hooking them a couple times at the end so the rest of the worm moves as it bounce along the rocks.Worms also ten to get hit by small fish that bite the end off the worm but smallmouth bass will attack a worm there is no mistaking a hit from a bass on a live worm.
You can keep the minnows in a bait well ,in the heat of summer we put a small block of ice frozen in a milk carton to keep them healthy.Worms need to be kept out of the sun and in a cool place.Softcraws are fine in a little water or bait buck in a cool place.