Did you just start a worgen for Cataclysm, and have no clue where to head next? You're not alone. I found as soon as I had gotten out of Gilneas, the starting zone for worgen, I had no real idea what to do. I was getting tired of the Kalimdor quests, making it difficult to level as I didn't know where to head next, and short of simply using the dungeon finder, getting XP was tough.
So I did a little research and learned that the basic flow of leveling in Cataclysm goes something like this:
1. Darkshore
2. Ashenvale
3. Stonetalon
4. Desolace
For Kalimdor, you'll follow those basic patterns for leveling. However if you are more partial to the Eastern Kingdoms, you'll need to do it a little differently, obviously. The leveling flow in that continent basically follows like this:
1. Elwynn
2. Duskwood
3. Stranglethorn
4. EPL
Remember that as you continue to level, it's a good idea to intersperse some dungeoning, as this will help you get more experience, good rewards to make leveling go faster, and also general group experience in playing your class. If you have heirloom gear from higher level alts, it's even easier to level through the dungeon finder system. However, the most efficient system is generally to do both questing and dungeoning.
Also keep in mind that it's a good idea to have a DPS spec, and what I call a "utility" spec. This means heals if you can heal, or tank spec if you can tank. This will translate to faster queue times when you do attempt to queue up for a dungeon, or for group quests or something. It's worth keeping in mind if you are planning to group much during your leveling experience in WoW, as a worgen.
One small note: as a worgen, you get a racial bonus to skinning, which does not provide the experience that other gathering professions (mining and herbalism, for example) do. When you find a node out in the world and you mine or herb it, you actually get experience now. This is a change that was made around the time Cataclysm came out.
Be aware that if you are leveling with heirloom gear, you may find yourself outleveling the content too fast for your quest log to keep up. It's a good idea to keep a map handy so you know what zones to go to. You can also check the Heroes Board any time you are uncertain of where to go next in the leveling process; these boards are scattered throughout capital cities, so you can always find one that will instruct you where to head next for your level.
Ultimately, leveling a worgen is a great way to see new content and the Cataclysm changes.