Tainted by the Scourge and home to the fallen city of Stratholme, the Eastern Plaguelands is a zone that plays heavily into the lore of "World of Warcraft." This befouled land is ideal for players level 40 to 45 looking to quest or farm up some profession mats, or to try for Baron Rivendare's skeletal warhorse in Stratholme. Horde players have a city much closer to the Eastern Plaguelands than do those of the Alliance, making the journey much shorter for them.
Alliance: From Stormwind
Head to the Dwarven District and board the Deeprun Tram. This instanced train will carry you from Stormwind to Ironforge, which is a bit further north than Stormwind and thus closer. The entrance is easy to spot; it prominently features many gears and a ramp leading slightly downward. Alternatively, you can also take a flight if you have the Ironforge flight point.
Ride out of Ironforge and turn east at the fork in the road. Follow this road to Gol'bolar Quarry, then take the fork north into Loch Modan. While at Gol'bolar Quarry, pick up the flight point.
Take the northern road when you come to the fork at Algaz Station and head through the tunnel to the Wetlands. Algaz Station is almost immediately outside of the tunnel from Dun Morogh, so your time in Loch Modan should be fleeting.
Take the eastern fork into the tunnel at Wetlands, then follow the road to Slabchisel's Survey. From here, take the road north and continue north at any and all forks, crossing the Thandol Span bridge into Arathi Highlands. Along the way, pick up the flight points at Slabchisel's Survey, Greenwarden's Grove and Dun Modr.
Follow the road north toward Refuge Pointe and head west at the fork in the road. At the next fork, turn north and ride through the tunnel into the Hinterlands. Pick up the flight point at Refuge Pointe along the way.
Follow the road north and take the western fork to Aerie Peak. From Aerie Peak, follow the beaten road leading north into the mountains -- this road leads to Western Plaguelands. Pick up the flight point at Aerie Peak before you move on.
Turn east once you get into Western Plaguelands and follow the coast around Darrowmere Lake. There's a point at the northeastern edge of the lake where you will shift into the Eastern Plaguelands, with access to the zone proper in a very small valley between the Eastern Plaguelands' many hills. Once you clear this valley, you're ready to begin your adventure in the Eastern Plaguelands.
Horde: From Orgrimmar
Board the zeppelin to Undercity. The eastern zeppelin tower in the Valley of Strength has a platform for zeppelins heading there. Undercity is the closest Horde capital to Eastern Plaguelands, and the only one that can be reached quickly and easily.
Follow the road east through the Bulwark and into the Western Plaguelands. Pick up the flight point at the Bulwark along the way.
Continue east along the road throughout the entirety of the Western Plaguelands, and cross the bridge over the Thorondil River into the Eastern Plaguelands. Pick up the flight point at the Mender's Stead along the way and enjoy your adventure in the Eastern Plaguelands.
Picking up all the flight points listed should make your next trip to these zones much shorter; you can jump on the flight point in Stormwind, Ironforge or Undercity and make your way to the Eastern Plaguelands without further input required.
The Eastern Plaguelands is a good zone for farming Silk Cloth, while the Stratholme dungeon is a good place to farm Runecloth. The Eastern Plaguelands is also a good place to farm Liferoot, and a decent place for farming Heavy Leather--although the nearby Western Plaguelands are better--and for farming the rarer Heavy Hide. It's not a bad place for finding Iron Ore, but not ideal compared to others.
Alliance players with Expert Riding and the Flight Master's License can fly northeast from Ironforge to reach the Eastern Plaguelands. During your flight, you may have to head due east for a short period to avoid flying over the deep water by the Wetlands, which will affect your fatigue and may end up killing you.
Horde players with Expert Riding and the Flight Master's License can follow generally the same path from Undercity as those without, although the trip should be a bit shorter.
Characters under level 40 may have difficulty in the Eastern Plaguelands, because the enemies will be stronger than you and your level may be too low for you to pick up any quests.