Hi i have a question on how many batteries i will need in my bass boat. i am going to have to run 2 humming bird 561 di's and a 55 pound thrust minnkota edge aswell as my live well and cranking the motor

If the Edge is a 12 volt motor you will only need two batteries.  The trolling motor, and only the trolling motor, is attached to one battery.  Everything else is attached to the cranking battery.  Don't worry, the cranking battery can handle the additional loads placed on it because the current draw from the other stuff is very small compared to the demands of a trolling motor; plus the cranking battery gets recharged every time you start the big motor.

Two batteries are plenty. Make sure that the Trolling Motor battery is a deep cycle marine with as many Reserve Amps (RA) as possible, Minn Kota recommends at least a size 27 battery for a 55lb trolling motor.