Peter over at Bayou Renaissance Man has a good article on how to prepare for a water outage.
Given that potable water is so essential (for drinking, cooking, and washing ourselves, our clothes and our cooking and eating utensils), we have to ensure we can get it when we need it. If the electrical grid goes down, every water purification plant and sewage processing plant is going to go down within a day or two. That means no more potable water out of our taps, so everyone is going to have to go get water from any available source.
It’s worth the read and includes some links to other printable resources everyone should have.
Link to purchase Aqua Mira, a water preservative.
Link for 5 Gallon Water Storage Jugs
Download this guide on water purification from the EPA.