The Aldor and Scryers have only one thing in common, they both are trying to rebuild Shattrath. To begin your allegiance with the Aldor or Scryer you must first talk to A'dal in the middle of Shattrath. If you are a blood elf you must talk to Haggard War Veteran located in the Terrace of Light.

"Reputation rewarded for killing mobs will no longer automatically deprecate. This means trivial mobs will continue to give out their full amounts of reputation on kill for the majority of cases in the game (level 70 creatures in Stratholme, for example, will continue to award the full amount of rep to level 80 players seeking to boost their Argent Dawn faction)." Patch 3.08 Notes.

Aldor Repeatable Quests

1. A Cleansing Light requires you to bring 1 Fel Armament to Ishanah in the Shrine of Unending Light of Aldor Rise in Shattrath, rewarding you 350 reputation through exalted. A good place to farm Fel Armaments is at Legion Hold in Shadowmoon Valley.
2. Marks of Kil'jaeden requires you to bring 10 Marks of Kil'jaeden to Adyen the Lightwarden located at Aldor Rise in Shattrath, rewarding you 250 reputation through friendly. A good place to farm Marks of Kil'jaeden is in the Bone Wastes and Nagrand.
3. Marks of Sargeras requires you to bring 10 Marks of Sargeras to Adyen the Lightwarden located at Aldor Rise in Shattrath, rewarding you 250 reputation through exalted. A good place to farm Marks of Sargeras is at Death's Door in Blade's Edge Mountains.
4. Strained Supplies is obtained from Sha'nir in Lower City of Shattrath. This quest is doable if you are trying to switch from Scryer to Aldor and rewards 250 reputation from hated to neutral.

Scryer Repeatable Quests

1. Firewing Signets requires you to bring 10 Firewing Signets to Magistrix Fyalenn located at Scyer's Tier in Shattrath, rewarding you 250 reputation through friendly. A good place to farm Firewing Signets is in Terokkar Forest at Firewing Point.
2. Sunfury Signets requires you to bring 10 Sunfury Signets to Magistrix Fyalenn located at Scyer's Tier in Shattrath, rewarding you 250 reputation through exalted. A good place to farm Sunfury Signets is at The Isle of Quel'Danas.
3. Synthesis of Power requires you to bring 1 Arcane Tome to Voren'thal the Seer located in the Seer's Library in Shattrath, rewarding you 350 reputation through exalted. A good place to farm Arcane Tomes is off of Blood Elves in Shadowmoon Valley and Netherstorm.
4. Voren'thal's Visions is obtained from Arcanist Adyria in Lower City of Shattrath. This quest is doable if you are trying to switch from Aldor to Scryer and rewards 250 reputation from hated to neutral.

Aldor One Time Reputation Quests

1. Aldor Quests (WoWWiki.com) / (WoWHead.com)

Scryer One Time Reputation Quests

1. Scryer Quests (WoWWiki.com) / (WoWHead.com)