The previous owner didn't have a clear label on basement switchboard, what is the safe and easy way to identify out which switch controls what lights/outlets? lights are probably easier, which turn on all lights and then switch on and off one by one. how about outlets? measure them one by one + switch on/off seems taking long time.

the previous owner had a 240 line run to the garage for a large compressor. He also had a transfer switch for a portable generator. Upon sale the inspector didnt like his wiring and flagged it. the owners (who had already moved out) hired an electrician to put in a new panel. The electrician removed the transfer switch , took the wire for the 240 line to the garage and cut the conduit back a foot from the panel. ( why? dont know) The rest of the conduit is there on a 30FT run to the garage and ends in a small terminal box. I would like to hook this back up for a 240 volt garage heater. So I need 10 gauge red, black, and green THNN to run through the conduit to the garage. I think I will establish a 240volt outlet, then run a plug from the heater to the outlet. a 30 amp breaker. Am i missing anything? any suggestions? I am in Kane county ,IL which is very different from the rest of the US when it comes to plumbing and electrical code.