This will depend on whether it is just the sockets or some lights as well. You need to check your consumer unit to see if anything has tripped. Modern consumer units have devices called RCDs which if they trip can stop multiple things working around the home. MCBs on the other hand will only cause just the sockets or just the lights to stop working. RCDs can generally be identified as they include a test switch and they are wider than an MCB.
If the RCD has tripped you should try turning off the MCBs to the left or right of it (depending on the manufacturer of the consumer unit) and then reset the RCD. If it trips again you will need to call an electrician. If it stays on, then switch on each MCB one at a time until the RCD trips again. You have now identified the faulty circuit.
In most cases if it's the socket circuit it will be something plugged in. Unplug all items on the faulty circuit and try to reset the RCD. If it stays on, go round and plug items back in, and when the RCD trips again you have identified the faulty item. If you are not confident in the above we recommend you call an electrician.