Call of Earth starts at level 4. There are two versions of the quest for horde, one in the tauren starting area and another in the orc starting area. As a result, trolls generally do the same one as orcs because they both start there. Technically, there's nothing stopping you from rolling a level 1 troll shaman and legging it to Mulgore (well, technically a level 1 orc shaman could do so, too) and taking the tauren quests instead. But for ease of discussion I'll just assume that tauren do the tauren starting area version and orcs and trolls do the orc starting area version. This is a basic quest which is fitting as it happens at a low level. You fetch some basic ingredients, are given a sapta, and go talk to an elemental. However, where it excels is in how it works to give you as a starting shaman player an idea of what your class is really supposed to be.
Often as players we get caught up in the mechanics of our classes... what gear we can use, what role we can fill, tanking vs dps... and forget that we're supposedly inhabiting a person in a completely different world. But when you first roll a shaman and perform this quest, it actually sinks in that you're playing a person who sees things no one else can see and does things no one else could do. Wind, fire, all that kind of thing! And it starts here, when a gigantic elemental materializes out of nowhere to talk to your tiny little self. It's the first inkling that you're playing a class with a unique role in the lore of the world. The alliance version is tailored more to the specifics of the draenei and their arrival on Azeroth, but it's a trifle less awesome in effect in my opinion.
Call of Fire is the level 10 quest chain to unlock the fire totems, and for many shamans it's the first inkling of the class' versatility. I know that for myself, gaining my fire totems made questing much easier just when it was starting to get tedious. No matter what horde race you're playing all roads on this questline lead to Kranal Fiss, the most unfortunately named Orc you're likely to meet. Go ahead, I dare you to go to the Barrens and start asking people if they know where he is. You thought Mankrik's wife was bad? The jokes about urine are just lurking in barrens chat, waiting to devour you. Anyway, Kranal sends you to Telf Joolam in Durotar. Telf fought hard for the title of most unfortunately named person in this questline and as runner up, he's the one who helps you out on this leg of the quest. You're off to kill Razormane spellcasters and Burning Blade cultists for drops to make a fire sapta, and then you're again exposed to the weird underlying clash of elemental forces that most folks cannot see. Strike down the manifestation of fire and light the torch and you're back to Kranal Fiss to wrap it all up and gain your first fire totem, the nearly ubiquitous Searing Totem. Once again I really like how this quest helps to define not only the shaman's role in the world, but how the clash of opposing forces in the world itself helps shape and define the shaman.
This time, however, the alliance version measures up. For starters, there's less running from the Barrens to Durotar and back, as all the action takes place in that draenei starting zone. Secondly, you're sent to the fire elemental Temper to help curb the ambitions of a would-be god formerly in its service. I love the names of the elementals in this one, and the sense that an out of control elemental is forcing moonkin to worship it, and you're sent to restore the balance helps show what shamans should consider themselves: mediators and peacemakers amidst the four elemental powers, helping to balance the necessary elements of earth, fire, water and air to bring about harmony and make life possible. Shaman have powers drawn from the elements, yes, but this power derives from their personal relationship with them. You're not taking power from the nether, you're not praying for the Holy Light or wrenching it from a Naaru or pacting with demons... you're a respected ally and sometimes, you have to step in and show your allies the truth. It's a really well done quest for both factions, and it really helps define the class.
Next up is probably the hardest of these questlines, Call of Water. I think the horde have it worse of the two, though, as you end up running all over Azeroth and Kalimdor including right into areas more or less covered with hostile night elves. You start off being sent to the Barrens to speak to Brine, an orc woman in a hut right next to some incredibly hostile quillboars. As you probably guessed from her name, Brine is related to the element of water (who knew that names as destiny worked in Azeroth, too?) and she'll be sending you on a series of quests all over the world. From the watering hole near her hut to Tarren Mill, then the Ruins of Stardust in Ashenvale (which is surrounded by level 23/24 elementals, making this a rough quest for a new level 20...if you can bring a friend it goes a little easier) and finally you're going to be sent across the ocean again to a shrine in Silverpine that's become fouled by the plague. Once again you have to whip some misguided elemental's ass and restore balance to things, whereupon the elementals of the area thank you for your help in healing the land, and give you a fragment of themselves to make a water totem. As the manifestation of water says, "Thanks to you. Thanks to the shamans. Corruption ebbs but life continues to wane. Up to shamans to protect life." The questline is not easy for a newly minted level 20, but accomplishing it really helps bring home that feeling that you stand at the juncture between opposing forces and it's your role to help restore that which is out of balance. In a very real way it's the shaman's task to protect and safeguard the land and those that depend upon it from corruption and imbalance, and the quest does an excellent job of showing you exactly what happens when there is no shaman to do his or her job.
The alliance version is different in tone, but similar in spririt. You descend to the depths of the ocean floor to speak to the great elemental Aqueous. I remember being surprised at the time to find a level 70 elemental down there. Aqueous is understandably disturbed at the pollution of the waters around Bloodmyst Isle and he wants you to do something about it before he gives you a water totem, so you're sent off to dispatch corrupted elementals, then to the Ruins of Stardust (at least you can travel directly through Astranaar if you're a draenei, so it's a trifle easier, but the elementals around the water you need are still a pain) and then you're sent to stop the pollution at its source, the experiments of Tel'athion the Impure. In gratitude, Aqueous grants you the pure water you'll need for your water totem. As in the horde version, you find yourself the agent and mediator of the elements, restoring the balance that (in this case) someone has deliberately tilted over. The added bonus is that you, personally, restore the esteem of the elementals of water for the draenei people, giving the quest more of an epic feeling than you'd expect for one starting out at level 20.
Finally we come to the anticlimactic quest Call of Air. The horde version is, well, boring. You go to Thousand Needles, you find a tauren in a cave, you get an Air Totem. Thanks for your time, young shaman.
The alliance version is clearly the superior experience. It doesn't require any more from you... you don't have to kill anything or perform any great deeds... but you get to speak to an Air Elemental who congratulates you on your wisdom and says there is no further need to test you, and you get to fly, so honestly it's a lot better than just going into a cave and having an old tauren hand you a totem from a stack he's got by the fire.
By the time you've reached level 30 and gotten all four totems, you've gotten solid experience in playing a shaman and, if you wanted, you learned quite a lot about the expected role a shaman plays in his world. I'd actually recommend everyone roll a shaman and take her or him at least to thirty just so you get to experience these quests. Heck, do two shamans, one horde and one alliance, that way you won't miss any of the elemental goodness.
Next week, at long last, elemental shamans take center stage.