When creating a death knight, players will begin in an instanced version of the Eastern Plaguelands (called the Scarlet Enclave) in the necropolisEbon Hold. Death knights are required to complete a fairly extensive quest chain before leaving the instance and joining the rest of the players on their realm. This instanced portion teaches them the skills of their class, upgrades their armor and weapons, and informs them of their place in the world while under the Lich King's power.
By the end of this quest chain, you will have all of the talent points for your level (58), a nice set of blues, and you will be able to go straight into Outland, however, your professions will be untouched (apart from first aid) and you may want to get those up to prevent having to go back later on and doing them at an even higher level