Black teas (or red teas as the Chinese refer to it) are fully fermented or fully oxidized teas. After the initial withering process, it is rolled to break down the cells of the leaf to expose the leaf's enzymes to oxygen. After full oxidation occurs, the leaf is then finished with forced hot air. 

To fully release the flavor of the black tea, it is recommended that fresh boiling or near boiling water be used.  
To prepare black teas, use 1 teaspoon per cup, add freshly boiled water and allow to steep 4-5 minutes.