Hi,
I'm a huge coffee addict and have often wondered this myself...
The flavored coffees usually do not have sugar in them. I buy the Millstone flavored coffees at Wal-Mart sometimes, the kind you can grind in-store (Chocolate Silk is good), and found out that they do not contain sugar. Makes me wonder how they get the flavor in there, but oh well, as long as I know it's sugar free I'm happy.
Coffee beans do have some carbs, though, in their natural state--approximately 1g per cup.