Preparing for freezing weather:
Know the location of the shut-off valve in your home or business. If you do not currently have a shut-off valve, have one installed as soon as possible.
Preparing outside your home or business:
Remove and store garden hoses.
Wrap outside faucets.
Wrap pipes in crawl spaces, under porches, garages, and any pipes that have frozen in the past.
Wrap pipes with dry newspapers, then cover newspapers with plastic wrap or garbage bags, and secure with string or wire. Commercially manufactured coverings are also sold at hardware and plumbing stores.
To wrap pipes that have frozen before, even though precautionary measures have been used, electric heat tape should be used.
Drain irrigation or water systems.
If snow or ice is forecasted, some customers may want to place a visible stick or marker by the water meter.
Preparing inside your home or business:
Open cabinet doors under sinks to give pipes next to outside walls exposure to warm air.
Find the faucet farthest from the main water line and allow it to drip cold water at a very slow rate in order to keep water moving through the pipes.
Vacant and Unheated Buildings:
Turn off the hot water heater and the main shut-off valve in the building.
Drain pipes by opening all indoor and outdoor faucets and then closing them.
Shut off the valve to each toilet and flush once to drain the tank (but not necessarily the bowl).
Thawing frozen pipes:
Thaw as soon as possible.
Do not use an open flame or hair dryer.
Wrap the pipe with rags and pour hot water over the rags.
Call a plumber or capable handyman to thaw frozen pipes or replace broken ones.
Make sure your irrigation backflow preventer is drained.
Here is a video on how to do this.