Whi h battery terminal to unhook ???'s

Pull the positive everytime.

You can even install a battery cutoff switch.

Well this one often gets different answers. The official answer when messing with your battery is to remove the negative first so if the tool you're using contacts the fender or other metal it won't short. Some airplane mechanics remove the positive first to allow any capacitance to discharge back to the battery.

As has been mentioned a disconnect is a good option, as is a "tender" or trickle charger.

Negative. If you take the positive off it charges your metal wrench and if you accidently ground it, Fourth of July.

Neither. Use a battery tender. They’re cheap and they work and keep the battery from sitting around not being cycled

Both at the same time.

I have battery cut off switches on both my cars but if they are going to sit for a while I put on the maintainer.
My Monte's switch is in the trunk but I put my Regal's under the hood and made a bracket for it.
I also have a remote solenoid which made it easy to wire in.

Negative!!!! Always disconnect negative first. Like mentioned above that way when you are lossening the positive post you cannot swing the tool into something and ground it out. Also if you are just winter storing it no need to start it just wait till spring. Without putting a load on it (driving) it takes a very long time to boil the moisture out

Always remove the negative terminal first. When removing the terminals the current will arc across the empty space. The negative terminal will arc from the battery to the terminal. The positive terminal will arc from the terminal to the battery and can cause the battery to explode if is gassing at that time. Seen it happen to other guys I worked with, grab them by the collar and walk them to the hose or the tire leak tank and dilute the acid.

If you want to discharge the electrolytic and tantalum capacitors remove the ground then remove the positive then reconnect the ground.