When considering how to store drinking water, a first step is for you to decide what your preference is in time and money spent on the containers you choose. You can go the professional route and store your drinking water in commercial containers or you can use the containers you may already have at home.
If you decide to go with commercially-prepared water containers that you plan to fill yourself, be sure to thoroughly wash out the containers with a sanitizing solution of one (1) teaspoon of common chlorinated liquid household bleach (with no additives/thickeners/scents) to every quart of water you use, remembering to wash the lids and the area around the mouth of the container (include the area where the lid screws on). You should be able to fill your containers with regular drinking water straight from the faucet, provided it has been chlorinated by a municipal plant. Otherwise, you will need to treat it yourself.
In order to treat water yourself, you will need to use liquid household chlorinated bleach (only the normal stuff, with no thickeners or scents or any other additives) in the quantity of one eighth (1/8) teaspoon for every gallon of water that you have. You should follow these same guidelines for any containers you choose to use that you have at home.
Two guidelines you will need to follow when considering which containers to use from home: Do not use any containers that used to hold milk of juice. For one thing, the milk containers tend to be brittle after some time, and for another, juice and milk tend to get into the plastic so that you can never really wash them out enough for your drinking water to remain safe. However, do consider using containers that had originally held soda pop.
There is also the option of buying your water containers pre-filled. When you do this, you will need to leave your containers unopened until you decide to rotate them (this means that you will need to use the water before the "expiration" or "use by" date on the bottle and replace them with fresh containers of clean water).