the place is a major point for farming crimson whelp(companion), but the mobs have an instant spawn point, so you can also use this as an advantage to level your alts. Simply buy another account yourself or pay somebody else to do the bid, lock is the best class to do the bid like all the time.
felblood intiates near the throne of Kil'jaeden.
I recommend this spot because it is again an instant spawn, could save you tons of time from questing, but I do not recommend going there untill lvl28 since the mobs in wetland has a decent chance of dropping the crimson whelpling.
You can choose to do a few dungeon b4 you hit 75 and can enter the hall of lightning or you can also choose the shattered halls (heroic)
However, I would not recommend the shattered halls because it is limited to hunter/mage only and require some technique that may be considered as exploiting.
just level to 75 and go to the hall of lightning.
After you kill the 1st boss.
You will find some instant spawn mobs again. (LOL) The Molten Golems.
Just aoe them down and they will keep spawning and that will get you to 80.
The best way I found at this level range is to ask a mage to teleport you to the shrine and fly you to the mistfall village.
You will find some mobs called Slateking troublemaker but that required certain dailies.
There are many other methods that may involve exploitation so I would not talk about it.
That is how you get your alt to a level of 90, no hack, no exploitaing, totally valid, and should take less than 24hours.