The Netherwing can be found at Shadowmoon Valley in The Outlands. Players begin their reputation at 0/36000 of hated. To get your reputation to neutral you will be doing the Ally of the Netherwing quest chain which is given by Mordenai in the Netherwing Fields.

"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.

Netherwing Repeatable Quests

1. Accepting All Eggs is obtained from Yarzill the Merc at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
2. Nethercite Ore is obtained from Taskmaster Varkule Dragonbreath at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
3. Netherdust Pollen is obtained from Taskmaster Varkule Dragonbreath at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
4. Nethermine Flayer Hide is obtained from Taskmaster Varkule Dragonbreath at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
5. Netherwing Crystals is obtained from Taskmaster Varkule Dragonbreath at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
6. A Slow Death is obtained from Yarzill the Merc at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
7. The Not-So-Friendly Skies... is obtained from Yarzill the Merc at Dragonmaw Base Camp in Shadowmoon Valley and rewards 250 reputation from neutral through exalted.
8. Picking up the Pieces... is obtained from the Mistress of the Mines at the Netherwing Mines in Shadowmoon Valley and rewards 350 reputation from friendly through exalted.
9. Dragons are the Least of Our Problems is obtained from the Dragonmaw Foreman at the Netherwing Mines in Shadowmoon Valley and rewards 350 reputation from friendly through exalted.
10. The Booterang: A Cure For The Common Worthless Peon is obtained from Chief Overseer Mudlump at Dragonmaw Base Camp in Shadowmoon Valley and rewards 350 reputation from friendly through exalted.
11. Disrupting the Twilight Portal is obtained from Overlord Mor'ghor at Dragonmaw Base Camp in Shadowmoon Valley and rewards 500 reputation from honored through exalted.
12. The Deadliest Trap Ever Laid is obtained from Commander Arcus (Aldor) at the Altar of Sha'tar in Shadowmoon Valley or Commander Hobb at the Sanctum of the Stars in Shadowmoon Valley. Completing this daily rewards 500 reputation from revered to exalted.

Netherwing One Time Reputation Quests

1. Netherwing Quests (WoWHead.com)