Kalu'ak Quests in Northrend Starting Zones
The best place to start your Kalu'ak reputation adventure is in either one of the starting Northrend zones - Howling Fjord or Borean Tundra.
In Howling Fjord, all of the Kalu'ak quests are located along the western coast. The first Kalu'ak you will encounter is located a bit north of the Ancient Lift - a tram of sorts that ferrys players down to an Island off the coast. Lunk-tusk is just south of Westguard Keep (Alliance quest hub), at 32, 47. He sends you on a quest to find Orfus of Kamagua, who is at the top of the Ancient Lift. You can actually proceed directly to Orfus, skipping Lunk alltogether, but you get 5,050 XP and 50 reputation for this short detour. Orfus will send you on a couple of quests, then eventually send you down to Kamagua where you will pick up a few more, along with a flight path. You will also notice that there is a dock that a sea-turtle boat will occasionally swim up to. The turtle, although slow, will take you to the Kalu'ak village in Dragonblight. I suggest doing both Borean Tundra and Howling Fjord Kalu'ak quests before venturing to Dragonblight, since both will provide you with quests that send you there for XP and Rep.
Through your Howling Fjord Kalu'ak adventures you will be sent to areas all over the south and west, including a pirate hub where you will find several more quests. Kamagua is also the area where you will eventually unlock the daily, "The Way to His Heart..."
Borean Tundra is a little trickier because there are a couple Kalu'ak quest line starting points that don't necessarily flow together well. One of these starts in Valiance Keep (A) or Warsong Hold (H). A member of your faction sends you on "A Diplomatic Mission" / "Seek Out Karuk", both of which send you to a Tuskarr named Karuk to complete a few quests for him.
Another Kalu'ak tuskarr named Etaruk can be found at 54, 36, East of Amber Ledge. He begins and ends three quests that will earn you reputation. Near him is a giant rock with the spirit of an ancient Kalu'ak, Elder Atkanok, possessing it. The rock beings and ends four Kalu'ak quests in the same area, so it is best to try to complete Etaruk and Atkanok's quests at the same time.
For Horde players only there are five quests given by Waltor of Pa'lea, found West of Warsong Hold by Garrosh's Landing.
Lastly you will find several quests at Kaskala, N/NE of Valiance Keep along the coast, including the Borean Tundra daily quest, "Preparing for the Worst". West of Kaskala you will find Unu'pe, another flight path, and another sea-turtle that will take you to Moaki Harbor in Dragonblight.