Levelling Locations: 11-20
Previously in the Levelling Locations series: 1-10
At level 10 you're deemed big enough to venture out into the wider world. You'll probably be sent to a capital city on a quest to experience the hustle and bustle of urban life, and you'll start seeing life outside the "newbie zones" for the first time. You also get access to better armour, including your first green (uncommon) items, and you can take part in the PvP Battlegrounds. In many ways, life begins at 10!
10-20
Horde
The undisputed king of locations to quest in for this bracket is the Crossroads, deep in the Barrens. It's not to everyone's taste--Alliance raids and low-quality General chat cause some players to avoid it completely--but if you like convenient questing, you've got it. From your first ride on a wind rider to battles against the centaur, you're well served for quests and only a short hop away from Thunder Bluff and Orgrimmar.
If you want to journey away from the Barrens, or you're an Undead player, Silverpine Forest is the place for you. The Sepulcher contains a number of quests to get you going, though if the scenery becomes too depressing you can always travel back to the Crossroads for some savannah sun.
Alliance
Alliance players don't have life as easy as the Horde, but they do have a little more choice. There are three zones to adventure in, during this level bracket: Westfall, west of Elwynn Forest, is a logical place for Humans to continue their journeys, although it mainly has quests for levels 12-20. Dwarves and Gnomes may continue from Ironforge to Loch Modan, and Night Elves will probably want to hop on a boat from Darnassus' Ruth'theran Village to Darkshore.
It's possible to quest in any of these zones, and most players will spend time in multiple zones for the full adventure, though Night Elves may wait to make the dangerous Wetlands crossing until later levels.
Instances
During this level bracket, you'll encounter several instances--these are fairly gentle, designed as an introduction, and it's a good idea to run them at least once. You'll get fairly decent XP, some nice dropped loot, and more importantly you'll learn a lot about playing your class in a group. Most of the quests you do will not need groups, so instances are a good way to get the party experience you'll need later, and help pass some of the later levels in this bracket.
Horde
Ragefire Chasm (RFC) -- Located in Orgrimmar, suitable for levels 15-20
Alliance
The Deadmines (sometimes called DM) -- In Moonbrook, Westfall, suitable for levels 16-24
Both
Wailing Caverns (WC) -- In the western Barrens, suitable for levels 16-22. This instance is easier to get to if you are Horde, and has more Horde quests, but NPCs above the instance and in Ratchet will give Alliance players some quests for it.
(These level ranges are approximate; you may get some quests earlier, and if you have a high-level group then you may be able to attempt the instance earlier, although be careful not to draw too much aggro!)
PvP
The XP you get from turning in Warsong Gulch Marks of Honor is fairly substantial at level 10, although you will probably die a lot in the process. However, if you venture into PvP at the upper end of the 10-19 bracket, you will probably feel invulnerable. Gaining XP this way, compared to questing, is less efficient--but you might find it more fun.
