Just do the quests in Souther dustwallow marsh.
hit tanaris, kill wastewander bandits, theives, assassins, summoners, etc. kill the two named mobs for the rewards. do the water quest where you spawn yourself some nice bettles, kill some southsea pirates, recover stoley's shipment, and, if you want to torture yourself, collect 20 pirate hats for each person.
hit hinterlands and do basically EVERY single quest there. pick up a quest in UC also to burn communication documents.
hit searing gorge and do pretty much alll the quests there besides the collection quests. you will be about 50 by the end of all that. you can also go back to tanaris to kill ogres now at around 45.
skip feralas.
skip ungoro. hit felwood instead. it will be a short stay anyway, esp with RaF.