Check your breakers box, or fuse box if you are in an older building.
Check for a tripped breaker. Normaly, you can tell just by looking at it: The switch lever is in a middle position and not toward on side or the other. Reset it by putting in the OFF position then back in the ON position.
If you have fuses, any blown fuse is realy obvious. Change it with a new one OF THE SAME RATING! NEVER EVER replace any fuse with one of a higher rating as it would create a serious fire hasard.
Electro, October 2012