The next time it is time to change the clocks for day light savings, take the opportunity to identify what each circuit breaker or fuse is hooked to. If you are working alone, plug a radio into an outlet or even light socket, turn it up loud and start flipping circuit breakers until it goes off. It will be faster working with someone who can just yell down to you when you find the right breaker. Most renovation centres now carry "electrical box lables" that are designed to put right on the circuit breakers, or on the box door for fuses. If you can't find these, or they don't have all the item you want, use Avery permenant lables or a lable machine.
One hint, don't lable things with names that may go out of date, like "Bob's room", which one day becomes "Office" or "Grandma's Room". Use "Front bedroom" or "East Room" or something that will last through transitions.