Deadheading flowers is simply the process of removing faded or dead flower blooms. In many plants such as day lilies, roses and azaleas removing these blooms promotes new flower growth by preventing the plant from putting its energy into the setting of the seed. This energy is then used to produce more flowers.
Snap off any faded flowers between your fingers and thumb, breaking the stem cleanly (for tougher stems use a pair of scissors or pruners). While certain plants may respond differently at the very least you will spruce up the appearance of your flowerbed by eliminating any dry ugly flowers.