Instructions
Acquire the Ace of Nobles through the Eight of Nobles. Only characters who know inscription can create noble cards, although you can purchase them from the auction house if any are listed. The Ace of Nobles is typically the most difficult to acquire and costs the most on the auction house. If you know inscription, you can create Noble cards by creating a "Darkmoon Card of the North." It's not guaranteed you'll create a Noble card.
Right-click one of the cards once you have acquired the Ace of Nobles through the Eight of Nobles to create the Nobles Deck. Right-click the deck to accept a quest. Click the "Calendar" at the right-top of your mini map. Look to see when the Darkmoon Faire begins and its location. Visit the Faire when it is in operation.
Talk to Professor Thaddeus Paleo at the Darkmoon Faire. Turn in the Darkmoon Nobles Deck and select "Darkmoon Card: Greatness" as your reward.