First, try resetting your circuit breaker. If that isn't effective, and a bathroom or kitchen outlet is affected, it could be a tripped GFI/GFCI. The GFI/GFCI is a mini breaker located inside an outlet within 10 feet of water (i.e., a sink). The GFI/GFCI reset button is usually red with test/reset noted on it; it is located directly on the outlet cover. The GFI/GFCI breaker prevents electrocution by shutting off power immediately if electrical current comes in contact with water.
These are most likely located:
Regardless of where it is located, it is likely that all the kitchen and bathroom circuits are connected through this outlet. Builders generally install one GFI/GFCI and then wire other outlets through it. Look in these areas for the GFI/GFCI and be sure the reset button is depressed.