Water your Compost
In order to make your compost pile a success and to provide yourself with a wonderful soil amendment, you will need a only few ingredients: organic materials (such as the aforementioned leaves, wood chips, grass clippings and produce), water and air. It does sound a bit magical, doesn't it? Well, here's the science: when your pile of carefully selected materials is kept well-aerated and at an appropriate moisture level, it will attract a group of microbes, such as beneficial bacteria and fungi, that will work hard to break your yard waste down into compost.
In order to help these magical microbes, you will need to keep the pile moist, but not wet: microbes need to drink too! The material in the pile should feel about as wet as a wrung out sponge. As the microbes work on breaking down the material that you have put into your compost pile, they give off a lot of heat. You will need to make sure that your pile doesn't get too hot (over 150oF) because this will kill the microbes and will stop the composting process. Since the pile tends to be warmer in the middle than on the outside, turning your compost with a digging fork or a shovel will help release the trapped heat. Turn your pile with the goal of getting whatever was in the middle to the outside and vice versa.
Turning the pile serves two functions: letting the pile cool and aerating it so that the hard-working microbes can get a breath of fresh air. Not all microbes need air to survive, but the ones that you want in your compost pile do. If you monitor the temperature of your compost pile regularly, keep it moist and turn it as needed, your finished compost should be ready after about three turns.
Finished compost doesn't have any recognizable "parent material" in it. So, if you see whole leaves, vegetable chunks and the like in your compost, it's not done yet! However, if your pile has finished composting, the compost is ready to put right onto your garden where it will do wonders for your soil and your plants!
For More Information:
Teaming with Microbes, A Gardener's Guide to the Soil Food Web by Jeff Lowenfels and Wayne Lewis, 2006. Timber Press, Portland OR. http://www.timberpress.com
The Green Web: The Beauty of Compost Heaps This link contains lots of composting tips including advice on what to put in your pile and techniques for easy pile turning.