Most likely one of your garden hoses will have a valve beneath it, like this:
Often you will find it near the front or back door. This will turn off the whole house. After you turn it off, turn ON the faucet. This will allow the water to bleed out on the ground, rather than in the house.
If you are not able to find this valve, you may also have a water meter box near the curb, or by your back fence.
It is worth noting that some jurisdictions do not want homeowners to turn this valve, but would rather have you call your water district to turn the valve.
Once you have the main turned off, you may be able to turn off an individual valve and restore service to the rest of your house. At most fixtures, you should have an angle stop that lets you turn off individual lines. Usually you will find them in beneath the fixture they are running.