Speak to Voren'thal the Seer inside the Seer's Library at the Scryer's Tier in Shattrath City. Performing quests for the Scryers will cause your Aldor reputation level to decrease.
Now that you've chosen a side, [player], you should meet the Scryers' leader.
You will find Voren'thal the Seer inside the Seer's Library at the Scryer's Tier.
See if you can be of assistance to him. He will be glad to hear you've decided to lend them a hand.