You can fish essentially any bait (that is legal) under a bobber, from herring and anchovies, sardines, all kinds of shrimp and prawns, squid, tuna, eggs, worms you name it.
Generally you want to be within 2 ft of the bottom, but that is not always where the fish are. there are many spots where fish suspend at different depths but as an average place to start keep lowering that bait till you find the bottom and then slowly work your way back up.