Starting Cataclysm - Mount Hyjal

Cataclysm starts out with the quest: A Personal Summons from  Naraat The Earthspeaker. This line takes you into Mount Hyjal Hero's Call.

Naraat the Earth Speaker in Stormwind.

Naraat the Earthspeaker will give the quest: Eye of the Storm. Click on the bowl to see into the water of the farseeing.

Next, part is in Moonglade.

Moonglade, Night Haven Emissary Windsong

Quest: A Hero's Call Mount Hyjal

Emissary Windsong at Night Haven in Moonglade will give the quest: As Hyjal Burns

Go see the dragon, Aronus to see what's burning.

He'll take you on a whirlwind tour.

Deathwing wants to eat you...

Deathwing brought a buddy... Ragnaros

Turn it into Ysera at Nordrassil

Pick up the quest: Protect the World Tree from Ysera in Nordrassil.

(Like you'd even have to ask us night elves to protect the world tree :P)

Don't forget to pick up the flightpath from flight master Fayran Elthas. It's a long boat ride back from Stormwind...

Pick up the quest: The Earth Rises from Anren Shadowseeker.

Tholo Whitehoof has the quest: Inciting the Elements.

Turn in the quest: Protect the World Tree to Malfurion Stormrage.

Malfurion Stormrage will give you two quests : War on the Twilight Hammer & The Flame Seer's Staff.

And now you're ankle deep in the Mount Hyjal quest line for World of Warcraft Cataclysm. Enjoy!!!