If all the power in your house goes off but you can see that your neighbors are still using hair dryers and watching movies, you know you’ve got an electrical issue in your private residence (as opposed to a general power outage in an entire neighborhood or district).
If you’re unsure what the issue is and can’t see or call your neighbors, go to your circuit breaker and check the main disconnect to see if it has tripped to the off position. If you’ve got a system that’s wired with fuses, pull the fuse block out and slip the fuses free so that you can test them with a continuity tester to see if they’re still functioning properly.
In the case of a general power outage, you can’t do much but contribute to the flood of calls likely overtaking the power company’s phone-in representatives. If your main breaker is still in the ON position or your main fuses are both good yet your neighbors have power and you do not, the problem likely has something to do with the electric system between your main entrance panel and the power transmission lines. In this case, you still can only really call the power company because this particular part of your system is their responsibility.
If you happen find a trip main breaker or blown main fuses in your main entrance panel, the problem has to do with your individual residence, and could potentially be serious. Don’t reset the breaker or replace the fuses in this case, as the problem might be a system overload (i.e. there’s more total current running through the system than the breaker is built to pass). Another potential reason: there’s a dead short somewhere in your house.
First things first, go through your house and turn everything off that turns off. Then, if you have a circuit breaker panel, flip all the breakers to the OFF position and reset the main breaker to the ON position. One by one, you can now try tripping the branch circuit breakers back on. If one of them fails to reset or if the main breaker trips off again when you trip a particular branch breaker back on, the source of the trouble is going to be within that circuit, which will need to be cleared of fault.
Now say all the breakers go back on and the main breaker stays on; what happened? You may have disconnected something earlier that was faulty and caused the power outage. Go back along the line and inspect each item for possible fault, plugging each one back in to see what happens. Either you’ll find the one causing the problem by noticing the issue visually or by noticing that the breaker tripped when you tried to plug it back in. Another possibility is that your breaker is suffering from systemwide overloading, meaning that you need to lessen the electrical load or install a larger main entrance panel with new branch circuits that can handle the electrical load you want. That requires a licensed electrician.