Level 20-22:
- Redridge Mountains [Lakeshire, Tower of Azora in Elwynn]
Again, do the easy quests in Redridge, which should take you up to level 21 or 22. Skip the more difficult quests unless you have a group for them. I'd skip the entire Stonewatch Keep area of quests just simply because that entire area itself is crap.
Level 22-30:
- Redridge Mountains [Lakeshire, Tower of Azora in Elwynn]
- Duskwood [Darkshire, Sven's Camp, Abercrombie]
- Wetlands [Menethil Harbor, Greenwarden, N. Loch Modan (The Algaz Gauntlet)]
- Ashenvale [Astranaar ?]
- Stonetalon Mountains [?]
- Elite Area: Dun Modr (Wetlands)
- Instance: The Stockades
- Instance: Shadowfang Keep
- Instance: Blackfathom Deeps
- Happy Loot: Naraxis' Fang (Duskwood)
- Happy Loot: Tiny Crimson Whelpling (Wetlands)
- Grind Area [26]: Dragonmaw Encampment (Wetlands)
- Grind Area [26]: Whelgar's Excavation Site (Wetlands)
- Grind Area [28]: Rotting Orchard (Duskwood)
- Grind Area [28]: Raven Hill Cemetary (Duskwood)
- Grind Area [29]: Vul'Gol Ogre Mound (Duskwood)
Preparation: Purchase Bronze Tube.
Start at either Duskwood or Wetlands. This is where "quest stacking" can come in really handy if you want to be efficient. There are many, many quests that send you to the same areas, and if you get all of the quests at once, you can knock all of them out without having to run back and forth. Considering Wetlands and Duskwood are fairly bad for having their towns on one side of the map and the quest mobs/areas on the other side, this saves a lot of time. A lot of these are parts of quest chains, so honestly it's hard to know if you don't have prior knowledge or do a lot of quest research beforehand - so don't worry about it too much, but try to be as efficient as you can. Once you finish one of the two new areas, you should be about level 25 and can go finish the harder parts of Redridge, and then finish the last zone.
Note for Stockades : There are 6 quests you can obtain for this instance. Lakeshire, Darkshire, Wetlands, Van Cleef note continuation (Bazil Thredd), and two from Stormwind.