Optional detours are marked. A stop is ticked once it's settled.
Spawn at Anvilmar with the Gnomes. First quests, no pet yet, just the starter weapon.
The rest of Dun Morogh. Carries you to level 10.
First real power spike. Grab a bear; it tanks for the whole run. Good moment for an Ironforge supply run and the first trainer visit.
Thelsamar is the hub for the teens. The two dungeons below are side trips, not the main line.
Right under Ironforge, the most convenient dungeon there is. First group run, and where Embrace of the Viper drops.
Sits inside Undercity's ruins in Tirisfal, so for Alliance it's a long run through Horde territory. The Alliance quests inside start from a dropped item that can't be shared. Worth it when already heading north, or for the story.
Next door to Loch Modan and the natural 20s zone for a Dwarf. Forever added quests here and a dungeon, the Excavation Site.
Stormwind-side alternative for the 20s. The Mor'Ladim chain is here, and so is Lupos, the shadow-damage wolf and the one classic rare tame that's convenient for Alliance.
Above Whelgar's dig in the Wetlands, easy to miss inside a zone you already know. Run it while questing here.
Ashenvale. Boat from Menethil to Auberdine, then south. First trip across the sea, so pick up Darkshore and Ashenvale quests on the way.
Inside Stormwind. Tram in, run it, tram out.
The old Dalaran in Alterac, north of Hillsbrad, reached from Southshore. One of the few new mid-level dungeons on the Alliance side of the Eastern Kingdoms.
Back in Dun Morogh. Sprawling and easy to get lost in, so budget extra time.
Tirisfal, the same Horde-heartland trek as Ruins of Lordaeron. Four wings, four visits: Graveyard 31–37, Library 34–40, Armory 37–43, Cathedral 39–45.
The headline new zone: nearly 200 quests and the neutral goblin port of Powderfuse. Built to carry the mid-game. Its outdoor dungeon, Krol'dok Stronghold, is listed as 40–45 or 40–55 depending on source.
Hidden new zone between Mulgore and Desolace, tied to the Shen'dralar. Blizzard named it with Riverglades and Hyjal as a better XP source than repeating dungeons. Level range unpublished; a mid-game Kalimdor detour.
Off the Stranglethorn coast. Pair it with Stranglethorn questing and Booty Bay. King Bangalash, the level 43 rare tiger, roams the northern jungle.
Re-check every slot. Compare Agility and the other stats piece by piece; the armor label on its own means nothing.
Badlands. Titan vaults and plenty of quest turn-ins. Broken Tooth, the fast-attacking rare cougar, roams here too, and drops the Flayed Hide if he's killed instead of tamed.
Mid-40s questing so the dungeons below aren't the only XP. Hinterlands, with the Wildhammer hub at Aerie Peak, is the friendlier of the two; Searing Gorge is denser and closer to Ironforge.
Tanaris. Gadgetzan next door has a neutral auction house, the new ship route to Riverglades, and Alchemist Pestlezugg, who sells Transmute: Arcanite. Worth noting for later.
Alcaz Island off Dustwallow Marsh, by boat to Theramore. Its level range makes the loot a candidate for gear that lasts into 60.
Desolace. Long, two-sided instance; plan a full evening. Snarler, a rare worg, roams Feralas just south.
The zone that ties the late game together: the Linken chain, Devilsaur Leather while Skinning is still learned, and Shaper's Terrace at the end. Worth questing properly.
The new endgame zone, with its own reputations and two raid entrances, Barrow Deeps (10) and Hyjal Summit (20). Home base for the last stretch.
New endgame dungeon in Azshara. Boss and loot tables not yet published.
New endgame dungeon in Un'Goro, the last one before the cap and a natural finish to the Un'Goro questing.
Sell the Skinning and Mining haul, unlearn both, and power-level Enchanting and Alchemy with the gold (see Trading). Move Legacy points to the Professions side. Barrow Deeps, Hyjal Summit and Onyxia's Lair open December 9 with no attunement for this tier; gear and consumables are the ticket in.