Of all the things that I am, for all of the multitude of alts that I have, one things that I've never been all that good at is writing leveling guides. I have a hard enough time as it is following said guides; writing out my chaotic leveling process is a chore and a half. That all being said, the one thing I do have enormous amounts of experience in leveling. I've nearly reached the full limit on the amount of characters that I'm allowed to have. Allow me, then, to impart some of what I know about bringing your fledgling warlock up to speed into the endgame. After all, while the journey might be half the fun, the destination is all so glorious. We do need someone to stomp on those pesky mages.
The first order of business is to know your spec going into the game. While all warlocks focus on damage (so we don't have quite the same complications as hybrid classes), which spec you choose to go with is still important. Affliction has long been touted as the prime warlock leveling spec, and that is still somewhat true. Affliction offers the best multi-target, fast-paced farming that can't be matched by any of the others. The downside to this is that mob farming has fallen the way of the dinosaurs in WoW leveling; instead, questing and running dungeons is far more efficient, and affliction doesn't have its strength there.