The Alliance quests in Ashenvale include several that want to send you into Stonetalon Mountains.
Faldreas Goeth’Shael – Journey to Stonetalon Peak;
Sentinel Thenysil – On Guard in Stonetalon;
Shindrell Swiftfire – Pridewings of Stonetalon.
The first section has you meet Kaela and Gaxim. They are to the south of your entry point to the zone, Windshear Crag, behind a bluff looking down on the pass south out of the crag. Collect Gaxim Rustfizzle – A Gnome’s Respite. Go back into the valley to the north and kill the humanoids (mostly goblins, I think). After you check back in with Gaxim, he’ll give you two more travel quests: Gaxim Rustfizzle – A Scroll From Mauren, and An Old Colleague. These send you to Stormwind and Ironforge, respectively.
Oncde you have these quests, continue on to the NW, along Webwinder Path, around Mirkfallon Lake, to Stonetalon Lake. Collect the new flight path, and complete your other quest here; try to remember that the only vendors in Stonetalon are by the griffons at Stonetalon Lake. The pridewings around the lake are level 20-23, slightly higher than the 19-20 uncommon young pridewings in the Crag. All can drop the venom sacs for the remaining quest, but they are uncommon at best. Watch out for the Pridewing Patriarch, a level 25 elite.
When you are happy, travel off to Stormwind and Ironforge. Next in line will be: Collin Mauren – Devils in Westfall, Retrieval For Mauren. Gaxim’s contact will ask you for 4 minor mana potions, and 2 minor fortitude. The latter can only be made via alchemy; there is one vendor for the mana potions, Dawn Brightstar in the Tower of Azora, in Elwynn Forest (limited supply). You should leave Stormwind with: Collin Mauren – Retrieval for Mauren.
When you get back, you’ll be given: Gaxim Rustfizzle – Covert Ops – Alpha and Covert Ops – Beta, together with a Covert Ops Pack, containing plans, 2 detonators (red and blue) and 2 explosives. Start with Alpha, the lumbermill NE of the deforestation machine. The plans are a scroll on a table/crate at one corner of the (open) mill. The wagon is south of the mill, with sparkling fireworks on top of it. It is best to position yourself between the wagon and the mine before detonating it. However… I wasn’t able to place the explosives, no matter what I did or where I stood. Instead, I just killed my way to the plans, which were at the SW corner of the lumbermill.
For Beta, the wagon is NE of the mine (which is at the west end of the lake). The letters are on a crate in front of the (lower, to the east) mine entrance; you do not need to enter the mine. The problem is that the mobs will run close to you and may very well aggro, and several mobs will stay behind; at least three of them were close to the plans. You also can’t get most of the subsequent quests without completing Covert Ops.
When you do, these two quests will be available to you:
Kaela Shadowspear – Enraged Spirits
Kaela Shadowspear – Wounded Ancients
Back to Mirkfallon Lake and take the west path with the three quests for Charred Vale; Enraged Spirits, Retrieval for Mauren, and Wounded Ancients. The elementals and basilisks are 23-28, ancients 25-27. However, there is a strict gradient in level, increasing as you get closer to Desolace. The elementals north of the Vale are 23 and rare 24, as are the basilisks. You will only find ancients in the Vale, where there is a high population density of 24+ harpies. The basilisk quest will go slowly if you don’t enter the Vale, but is still very possible to complete at a low level.
You can then take: Kaela Shadowspear – Update for Sentinel Thenysil (in Astranaar, Ashenvale), which leads to: Sentinel Thenysil – Reception from Tyrande (in the Temple of the Moon, Darnassus).
The mob density in the Charred Vale and Windshear Crag make this area tough for the appropriate levels, and the Covert Ops quests didn’t quite work out for me (or for many others, who have posted on Allakhazam). There is also a LOT of running around to get started on the series quests.