For a full-bodied cup of coffee, use two tablespoons of ground coffee for each 6 ounces of water. This produces a strong coffee, similar to what you find in specialty coffee stores. Read How Espresso Machines Work to learn how to make a shot of espresso.
Another trick to a great cup of coffee is fresh, cold water. It needs to be heated to around 200 F (93 C) to extract all of the flavors of the ground beans. Your automatic coffee maker will get the water hot enough. Be sure to keep the coffee maker clean (a periodic vinegar rinse does the trick) so that it not only keeps the water pure but also operates at its most efficient.
Decaffeinated coffee is made by washing the caffeine out of beans in one of two ways, both done before roasting. In one method, a chemical solvent is used to extract the caffeine. The solvent is completely washed out before the bean is dried. The second method uses water to steam the beans, and then the outer layers, rich in caffeine, are scraped way. See How are coffee, tea and colas decaffeinated? for details. There is one naturally decaffeinated coffee: the Madagascar coffee species mascarocoffea vianneyi produces decaffeinated beans.