Northrend

So I find myself for real in Northrend and so much going on that I have not had time to retell my stories of adventure, dungeons, dragons and the scourge. But I will, and I will soon.

But for now I recommend leveling like this;

Level 70-72 in Borean Tundra
Level to 74 in Howling Ford
Level to 76 in Dragon Blight
Level to 77 in Grizzly Hills
Level to 78 in Zul'Drak
Level to 79 in Sholazar Basin
Level to 80 in Storm Peaks
and finish off in Ice Crown

If you're going to Northrend as a Level 68 then still use the guide, just more work in Storm Peaks and Ice Crown to get to 80.

And a note for Death Knights, I would strongly recommend leveling to 60 in Eastern and Western Plaguelands. Its quicker, easier, and less camping for Quests.