The Aldor is one of the factions you may choose to ally yourself with as you enter Shattrath city. In WoW, players want to be strong and powerful, strength of ally is necessary. For example, if you have joined to a good guild, you will have more opportunity to get wonderful rewards (WoW gold, infrequent items, exclusive equipments and expereince). Both Horde and Alliance can be Aldor, although Blood Elves will be Hated initially thanks to the lore and how both factions came to be. Although there is no set best faction to support, Aldor generally favors Healers with their inscriptions and the spellthread recipes at Honored and Exalted.
It is worthy of note that you cannot be on friendly terms with both factions at once. Due to the way it is set up, if you complete quests for either faction your standing with the other will lower substancially more, making it mathematically impossible for you to have favor with both at once. Of course, you are not only get reputation, but also World of Warcraft gold and experience (WoW power leveling), if you have completed quests. You will always lose 10% more than what you earn with the opposing faction.
Hated to Neutral
Should you find yourself Hated or below Neutral with the Aldor, you will need to find Sha'nir in Lower City and accept her quest, Strained Supplies. This will make you go hunt Spiders in Terokkar for their Dreadfang Venom Sacs, and you may repeat this quest until you reach Neutral. Each turn-in of 8 Sacs will net you 250 reputation with the Aldor and substract you 275 reputation with the Scryers.
Neutral to Honored
Until Honored, the best way to earn reputation will be to turn in Marks of Kil'jaeden, worn by lower-level demons and other demon-aligned monsters. 2 camps in Auchindoun that have Burning Legion followers and Kil'sorrow Fortress in Nagrand are both good spots. Also worth noting is that should you grind monsters in Kil'sorrow, you will also be bumping your Kurenai or Mag'har reputation since they're enemies of these tribes in Nagrand as well. And the best way to earn WoW gold will be to buy from other places. If you are lack of WoW money, welcome to buy WoW gold from our site—Vcsale which is the professional WoW goods supplier site.
Honored to Exalted
Once you have reached Honored, you can choose to complete as many quests as you can for the Aldor, including and most importantly the lengthy line in Netherstorm's Area 52 - you will also be able to turn in Marks of Sargeras and Fel Armaments by now. Therefore, you are able to gain much World of Warcraft gold and other rewards. Sargeras Marks act the same was as Kil'jaeden's but should only be turned in from Honored and above. Fel Armaments will net you 350 reputation each, and will get you some dust needed to buy some of the Aldor inscriptions.
Reputation Numbers
The Aldor don't necessarily have any dungeons you can visit for reputation each kill you make, however, it is recommended to visit Shadow Labyrinth since it has a very high concentration of demonic monsters which will likely have a lot of Marks of Sargeras, along with more common Fel Armament drops.