Isaac's Sunrader

Hi, I'm Isaac and I just picked up an '86 Sunrader. All the electric stuff works when the extention cord is plugged-in, but there was no aux. battery in the rig when I bought it. Can someone please provide me with some advice on how to hook an aux. battery up? There are two red wires and two black wires in the side battery space. I'm assuming that both the red go on the positive post and both the black go on the negative post of the battery. But I want to sure and not mess anything up! lol! This is a really basic question I know, but I would very much appreciate a reply from anyone who has the time and inclination. Also, any recommendations on what kind/brand of deep-cell battery to buy? Thank you very much, Isaac :-D p.s. I will try to figure out how to receive replies via this forum, however my email address is: isaacbarham@yahoo.com Thank you!!!