Battery Charging

My Barracuda is presently in storage and I'm about to bring it out for the summer. I pulled the battery out today and brought it home. I've never charged a battery out of the vehicle. Normally, I put the red clip (+) on the positive post and ground the black (-) on the engine block. Where does the black get placed in the absence of the block. My immediate thought is on the negative post but I thought I'd check in first. Thanks