Usually this results from air in the pipes.  There may be other reasons, like a loose washer, but air in the pipes is the most common cause.

Turn the on the water faucet.  While it is on, turn OFF the main water valve and the water will shut off.  When you turn on the main water valve, any air in the pipes will be flushed out.  If this does not solve the problem, you will need to call a plumber.