Can someone please tell me what wire(s) to disconnect to render a baseboard heater inoperable? I think it's a Dayton heater, about 4' in length. The heater itself is one of two that run off the same thermostat, and I want to shut one off since it's directly behind my armoire which holds the TV, DVR box etc, and I don't want any heat behind it. (I'm female, and don't know squat about it). Thanks!

Since you have 2 heaters, it's hard to know how the wiring is done. I also note you "don't know squat". So it is difficult to recommend you going into a 240 volt circuit, taking out some wires and hoping you did the right thing. If there is a thermostat for each one, turn off the one behind the armoire. Remember, you won't get any room heat. Can you move the armoire to another location? If you are sure you want to go ahead, I will give you some general ideas of how they work. Good idea to have another person present! First, identify the fuse or circuit breaker and make sure the power is off. Turn on the heaters to make sure they do not heat. Move the Armoire out of the way, and remove the metal cover over the heating elements. Some snap in, some screw on. You should see three wires connected to a small panel. Usually they will be black, white with black tape or black markings and a bare or green wire. Sometimes they are black, white and bare/green, sometimes you will see a black, red and bare/green. Remove the black and white or black and red so only the bare/green wire is connected. Screw on wire nuts over the 2 disconnected wires, wrap some black tape around the wire nuts and fold them out of the way. Replace the cover and replace the fuse or reset the breaker. Turn on the heater and only 1 should work.
Unless you feel very confident doing this job, get an electrician or experienced handyman. BE CAREFUL

Is this in your home and not an apartment or co-op?

Are the baseboards on their own breakers or are they sharing one breaker?

How are the heaters connected to the thermostat?

You might want to contact a local licensed electrician to get a bid. This would be a fairly straight forward task.

If they are on their own breakers, the easiest thing to do would be to open (shut off) the breaker for the heater that you want off.

Pictures would help me, I can't speak for anyone else.

Thanks for all the info you sent me. I did everything you said, and am happy to say it worked, and I wasn't electrocuted! Now when I turn the thermostat on, the heater I wanted to use works! Thanks again!! I'll use this site often!

Glad we could help, Brian-ma0641