Are you leveling your first Alliance character in World of Warcraft? In that case, working with an Alliance leveling guide would be the best, because it's the only way you won't miss any of the Alliance leveling areas Cataclysm has brought to the game.
Anyway, in this post I'm going to point out a few quest hubs in the Cataclysm zones that you shouldn't skip when leveling up an Alliance character.
<b>Mt. Hyjal.</b> This is the area that you should choose for starting the 80-85 content. The first camp where you should be questing is Nordrassil, then you will be sent to Shrine of Goldrinn (no flight master there), next Shrine of Aviana, Grove of Aessina (plenty of quests here), Sanctuary of Malorne (first phase), Scorched Plain (no flight master here either), Forge of Supplication and then Gates of Sothann.
It's really important to start from Nordrassil and follow the directions the quest givers provide if you're not using a leveling guide, because otherwise you might miss some of the small quest hubs between these major locations in Hyjal. Also, keep in mind that there's a lot of phasing in and out between the zones of Mount Hyjal, and some of the areas will change after you complete certain series of quests there.
I usually remain here until I finish all the quests in this zone, to become revered with the Guardians of Hyjal. This way I'm eligible for buying some nice level 333 items, usable at level 83.
<b>Vashj'ir.</b> Now, usually in this zone I come only to get the Sea Horse mount, just to have it and after that, I simply move to Deepholm. Anyway, if you complete all the quests in Hyjal and some of the quests in Vashj'ir, until you get the water mount, you should be close to level 73, ready for Deepholm.
Anyway here are the quest hubs that you should visit in Vashj'ir. The Vashj'ir Alliance leveling areas Cataclysm has brought to the game are: Legion's Fate and Smuggler's Scar in Kelp'thar Forest and Silver Tide Hollow in Shimmering Expanse, to unlock the Earthen Ring camp. You might need access to the Earthen Ring quartermaster, at least for the tanking head enchantment, and that's why it's best to quest in Vashj'ir until you reach this area.
Once you unlock the zone at Silver Tide Hollow and get the travel point you should move a bit north, to Sandy Beach and also discover that travel point there. Who knows when it might be useful.
Anyway, to know exactly which camp to go to, which quests to do and which to skip, and to know exactly how to complete each and every objective, can only be achieved by following the leveling path of an Alliance leveling guide.