In addition to searching the forums as Deb suggested, here are some articles from the Dollar Stretcher:
Recycling Gray Water
Here's part of an article I wrote some time back:
* Wash your car quickly with a bucket and a rag, then a quick rinse with the hose. (A step ladder will help reach the center of the top.)
* Fill the kiddie pool, but when it's time to empty it, use the water for flowers or garden, or a dry spot on the lawn. Or wash the dog in it.
* Never water lawn or garden in the afternoon heat. Much of the water will just evaporate instead of soaking in.
* Drip irrigation is much more efficient for vegetable or flower gardens. Least efficient is sprinklers that spray far into the air.
* Catch rain water to use for watering things later, or for cleaning. If you live in the country, you can use rain water to wash your hair or face. In the city, soot and air pollution may not allow this.
Inside, water can easily be wasted any time, but when the weather is hot, the demand for water increases quickly. To help combat that (remember that even small amounts are helpful), get frugal with the water.
* Use less to mop and clean with. Not only will you save on water, you'll save on soaps and detergents because it will take less to treat less water. Even if you decrease the amount by a quart, it will add up to several gallons over a month.
* Limit shower time, but choose a shower over a bath any time it's possible.
* If you wash dishes by hand, pay attention to how much water you use to wash, and how much you use to rinse. As a general rule, it takes less to rinse dishes in a container of water than in running water, but it can be done for less by rinsing a full sink of dishes at one time. Remember the ones underneath get rinsed without extra water!
* Only wash full loads, whether that means dishes or laundry. A 'half' load of either uses more than half as much water. Besides that you'll save electricity (or gas).
* Get in the habit of being stingy with it. For instance, use the water left in a glass after ice cubes have melted to water house plants. Use your own glass of leftover water to microwave for a cup of tea. Think twice before disposing of any water.
* Keep a bowl or container in the kitchen sink to catch water that would otherwise go down the drain. This can be used to wash dishes, mop the floor or clean otherwise, or to water plants. You'll be surprised how much water goes unused down the drain.
* Low flow showerheads and low water use commodes will both contribute to a lower water bill.
* Fix any leaking faucets as soon as you can. If you must put up with one for a day or two, put a container under it and use the water for any household purpose.