Like anything else, there's good and bad with coffee. The bad would be for specific health issues and/or when coffee is one's main drink of the day. The good is that it's delicious and a nice little pick me up in the morning or early afternoon. There are people here who can give you more specifics or you could google "health benefits of coffee," and "negative impact on health from coffee."
A cup or two a day most likely won't hurt you, especially if you drink a decent quality coffee. A pot a day of Folgers will probably leave you feeling like crapola.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine