Question about Dual Battery Set up (SOUND SYSTEM NOT A PROBLEM)

hi I'm phil i am trying to hook up a dual or multi battery setup anyone have any advice
i want to run two or three to pull a full camper set up keep in mine i know nothing about marine batteries or isolators

what would be the first step to start on this project

i will be pulling a truck camper

why do you want multi batteries ? to run stuff in the camper while you are parked I would suppose ... You can use an isloator or I have seen just using diodes. I guess the first step is to decide where you are going to mount the battery(ies)

here is a link to another option to an isolator ... http://www.hellroaring.com/nodiode.php

I don't know about isolators, but I had a similar arrangement where I jumpered the two batteries together through a relay controlled by my fuel pump (or other circuit which only comes in while the vehicle is running).