You can attract worms in your own yard or garden by making a worm-friendly pile of mulch, or you can buy commercially available red wigglers or other red worms, smaller than their night crawler relatives but favored for worm composting. Also called vermicomposting, this is an increasingly popular method among organic and home gardeners to produce high quality compost in a small space. This method is for indoor use, in a shed, garage or basement.
Build a worm composting bin, or buy one if you prefer. They are easy enough to make by punching holes in the bottom of an existing plastic bin such as a large Tupperware or other container. It should not be clear, because worms like it dark. Make a dozen or so holes in the bottom, and another eight to 10 in the sides near the top for air circulation.
Find a cool location for the bin. Worms like it at about 50 to 60 degrees, so an unheated annex to a heated building is good in the winter, or a garage or shed may provide the right temperature. Put the bin on a plastic tray such as a cat litter pan or other holding tray for easy cleanup and discouraging worm escapes.
Create worm bedding for the worms. Soak old newspapers, cardboard or even junk mail in water and tear it into small pieces. Be sure there are no sharp staples or glossy papers in the mix. Fill the bin about four inches deep with this material. Then add some starter food; a gallon or so of rich compost or organic, loamy soil. Avoid sand, which is abrasive to the worms.
Add worms after a day or so of letting the bedding and compost mixture sit. Add night crawlers, red wigglers, earthworms, or common red worms. Any of these will produce rich soil from the compost. The smaller red worms are less adventurous in captivity, however, and are preferred by many because they don't make a run for it when you open the bin. Snap the lid on tightly to make it dark for the worms.
Feed them grain-based foods at first to get them adjusted to their new home. Oatmeal, cornmeal, old bread or cooked rice all are good starter foods as they will decay quickly. Later, add any kind of kitchen waste, including coffee grounds, vegetable scrapings, rotten fruit, and so on. Wait until food on the top of the bin disappears to add more. If the surface dries out, add a little water once a month to keep the bedding moist.