Keying for Karazan?

[Guest]

Finaly made it to level 70. What should I start working on now to be getting myself keyed for Karazan or other end-game stuff?

[Guest]

Start with the quests given to you by the npcs at Karazhan. They will chain through all the subsequent requirements for the keying process.

[Jivundus]

To begin keying for Karazhan, go to Deadwind Pass in old world, and then speak to the NPC's outside of Karazhan itself. There will be two quests, these are the start to becoming keyed.
As for other instances, there's really nothing that cant be accessed via other players with a key besides the Heroics which everyone needs a key.

These following keys are useful to have, but can be bypassed.
Shattered Halls- Key quest starts of a NPC in Shadowmoon Valley, Smith Gorlunk.
Shadow Lab- The key drops on the last boss of Auchindoun third wing Sethekk Halls.
The Arcatraz- Accessible through a quest chain for the key that requires you to complete both Mechanar and Botanica, that begins with a long quest chain called "A Heap of Ethereals" from Nether-Stalker Khay'ji in Area 52.