From wow.incgamers.com

Background

"Throughout history, many have given their lives to aid their allies. Every year, members of the Horde and the Alliance set aside time to honor the memories of the fallen and to pay tribute to those whose memories are held most dear: Uther Lightbringer, for the Alliance, and Grom Hellscream, for the Horde. Heroes take time from their adventures to visit the graves of these two great persons and to leave a tribute to them at the memorial. To show their respect, members of the Alliance light a candle at the Tomb of Uther Lightbringer in the Western Plaguelands. Members of the Horde show their respect to Grom Hellscream by leaving a bottle of spirits at the base of the Hellscream Memorial in Demon Fall Canyon in Ashenvale.

Also, adventurers can see the spirits of the fallen outside of Orgrimmar and Ironforge and can take a moment to heft a mug of Harvest Nectar to their memory. Other harvest foods are laid out on the tables as well, for those who have made the perilous journey to their hero's tomb to pay him tribute. Adventurers can satisfy their hunger on Harvest Fish, Harvest Fruits, or Harvest Boar, as well as quaffing some Harvest Nectar." ~ Blizzard

Locations

The festivals take place outside Ironforge and Orgrimmar. Players will notice spirits of fallen heroes by tables laid out with food, which can be picked up and used.

Activities

Outside Orgrimmar and Ironforge, tables are covered in food and drink for players to take and use. The refreshments available are shown below:

[Unknown Item: Harvest Boar]	[Unknown Item: Harvest Fish]
[Unknown Item: Harvest Fruit]	[Unknown Item: Harvest Nectar]

Players can also speak to quest NPCs near the festival tables outside Ironforge and Orgrimmar, depending on their faction. At Ironforge, seek out , at Orgrimmar, look for . These characters will give quests to honor past Heroes.

Quests

. Travel to Uther's Tomb in Western Plaguelands and use Uther's Tribute at his statue, and then return to Wagner Hammerstrike outside Ironforge before the Harvest Festival is over.

. Travel to Grom's Monument in the Demon Fall Canyon of Ashenvale and use Grom's Tribute at the base of the monument. Return to Javnir Nashak outside Orgrimmar before the Harvest Festival is over.

Rewards

Alliance players are rewarded with [Unknown Item: For the Light!].

Horde players are rewarded with [Unknown Item: The Horde's Hellscream].

Every player who took part in the quest will receive [Unknown Item: Bounty of the Harvest] in the mail two days after completing it.

Gallery

Images of the Harvest Festival
Alliance Quest Giver	Fallen Hero of the Alliance	Fallen Hero of the Alliance	Fallen Hero of the Alliance
Fallen Hero of the Alliance	Horde Quest Giver	Fallen Hero of the Horde	Fallen Hero of the Horde
Fallen Hero of the Horde	Fallen Hero of the Horde	Ironforge Feast Table	Orgrimmar Feast Table

Further Reading

Official Page