Coffee is prepared from roasted coffee beans, primarily of two varieties - Arabica and Robusta. Arabica beans are considered to have better flavor but are more susceptible to disease. Robusta beans have less flavor but more caffeine and are hardier. The document also discusses different roast levels from light to dark and various brewing methods for coffee including espresso, French press and auto drip. It emphasizes the importance of using high quality beans, freshness, proper grind and water temperature for best results.