Cabonite or Quest Helper are wonderful ( I'm using cabonite because an earlier version of QH had a really bad memory leak, my friend says that the memory leak has been fixed though and he prefers QH )
you probably want to complete this whole quest chain http://wow.allakhazam.com/db/quest.html?wquest=10119, you get a nice blue that lasts you quite a while somewhere in the middle of it.

leveling has been increased from 60-70, previously you could do all of the quests for hellfire and be level 62 at best, I didn't do all of them with my latest team and was level 63.5
that including doing both dungeons for ramparts and blood furnace ( shaman + 4 hunters ) at 63.
I finished most of zangarmarsh and I was level 66.
per say I was rested for quite a few places like the dungeons and that does speed leveling up.