The only thing you need to have a Death Knight is you have to have at least one character that is level 55 already. Then you go to Create New Character screen and create one. That's it. That's all. Easy. You start off in DK noob area that has several quests that get you to around lvl 58 by the time you are done, then you revolt and go to your respective capital city (Aliance or Horde) and make piece with them.
When you enter the city you get rotten food thrown at you. People spit on you, etc....
After you talk to the King, then they like you. Funny thing is, EVERY DK has to talk to King before they are liked. Seems like one could do it for all of em. But, that's how the last DK noob quest is written, so that's what you do.
Oh, one last thing. It's not just you that revolts, it's a group of DKs. So you keep the flying thing and you get a port that takes you back there for training and stuff. Your flying mount is a dead griffon. No feathers, just bones. Heh hee.
Figure the rest out for yourselves and happy hunting.
Elvinbain (The Scryers)