The Dark Moon Faire appears monthly, early each real time month. It alternates between Elwynn Forest and Mulgore. When it is set up, a barker will appear in each major city to let you know it is active.
Vendors
Stamp Thunderhorn - Food vendor
Lhara - Exotic Goods. Most of her goods are limited item sales.
Sylannia - Drink Vendor
Professor Thaddeus Paleo - Exotic Goods. Except for the vials, all of his goods are limited item sales.
Flik - He sells some pet frogs and a leather ball.
General Quests
Spawn of Jubjub results in a pet jubling.
Sayge will read your fortune. You answer a series of questions and then receive a random stat buff. Afterwards, you can request a written fortune. Most of these are just funny sayings, but fortunes 23, 24, 25 and 27 all start up new quests.
Card Deck Quests
Cards drop in various high end dungeons. They are tradeable, so they can also be purchased through the AH. A set consists of the standard playing cards Ace through Eight. To get your reward, you must collect all 9 cards and combine them into a single deck to turn in to Professor Thaddeus Paleo.
Darkmoon Beasts Deck reward: Darkmoom Card: Blue Dragon
Darkmoon Elementals Deck reward: Darkmoon Card: Maelstrom
Darkmoon Portals Deck reward: Darkmoon Card: Twisting Nether
Darkmoon Warlords Deck reward: Darkmoon Card: Heroism
Quests Resulting in Tickets:
Tickets are bind on pick up. Anyone can do the tradeskill quest turn ins.
All quests are repeatable. Each turn in is worth 100 Darkmoon Faire reputation points. (110 for humans), most quests have a reputation turn in limit. See each individual quest for information. 20 Ticket quests have no limit, and have a follow up quest associated with them.
General (from Yebb Neblegear)
1 Ticket - 5 Small Furry Paws
4 Tickets - 5 Torn Bear Pelts
8 Tickets - 5 Soft Bushy Tails
12 Tickets - 5 Vibrant Plumes
20 Tickets - 10 Evil Bat Eyes
Blacksmithing (from Kerri Hicks)
1 Ticket - 10 Coarse Weightstone
4 Tickets - 7 Heavy Grinding Stones
8 Tickets - 3 Green Iron Bracelets
12 Tickets - 3 Big Black Maces
20 Tickets - 8 Dense Grinding Stones
Engineering (from Rinling)
1 Ticket - 3 Copper Modulators
4 Tickets - 7 Whirring Bronze Gizmos
8 Tickets - 36 Green Fireworks
12 Tickets - 6 Mechanical Repair Kits
20 Tickets - 6 Thorium Widgets
Leatherworking (from Chronos)
1 Ticket - 3 Embossed Leather Boots
4 Tickets - 3 Toughened Leather Armor
8 Tickets - 3 Barbaric Harnesses
12 Tickets - 1 Turtle Scale Leggings
20 Tickets - 8 Armor Kits
Ticket Rewards
5 Tickets can be turned in for a Darkmoon Flower.
5 Tickets can be turned in for a Minor Darkmoon Prize.
10 Tickets can be turned in for a Last Month's Mutton.
12 Tickets can be turned in for a Lesser Darkmoon Prize.
40 Tickets can be turned in for a Greater Darkmoon Prize.
50 Tickets can be turned in for a Last Year's Mutton.
50 Tickets can be turned in for a Darkmoon Storage Box.
1200 Tickets can be turned in for an Amulet of the Darkmoon.
1200 Tickets can be turned in for an Orb of the Darkmoon.