Shamans only get a couple of non-talented abilities after Chain Heal at 40. At 42 we get Grace of Air, which I use constantly when soloing on my enhancement shaman. To be honest, I never drop a windfury totem for myself, why would I when windfury weapon is much better? I drop it when I'm in a group with a lot of melee DPS - you should see how high a dual wielding warrior's DPS can go with a WF totem down - but for soloing or in a group with a rogue and a hunter as main DPS, GoA can produce some very nice results. It's a huge dose of agility, which is ranged attack power and crit for hunters, some AP and crit for rogues, and still respectable crit for any other melee. I'm a big fan of GoA and actually had to retrain myself to check group makeup and drop WF when it was justified, (If you ever get a really cocky DPS warrior in a group and want to humble him, don't drop WF totem and watch him sulk. It's hilarious. This message brought to you by a shaman with two DPS warriors.) I especially love the dodge bonus of GoA when soloing, as I'm perfectly fine with not being hit while I hit. All around, a lovely totem.
The last non-talented ability you'll be getting before 60 is Tranquil Air Totem. Clearly, to use this totem in a five man would require cooperation and coordination among your party, and so it's not the easiest totem to drop. But if you're in an all-DPS group, especially an all-caster group willing to forgo Wrath of Air. It can be a viable alternative totem to keep the DPS less threat-spike happy. I usually get stuck tank healing in my raids, so I don't drop this much. Tanks don't like threat reduction. It's funny. I don't pretend to understand it, but it upsets them when the paladin gives them Blessing of Salvation and I drop Tranquil Air next to them. Warriors are such contrary beasts.
Totem of Wrath is one of two elemental talented abilities, and as it takes 41 points in elemental to get, now is the time to be discussing it. It's a nice totem: I liked playing with it when I went elemental, and I very much enjoy it when I'm DPSing as enhancement. The other day I ran Botanica with a four shaman, one warrior group. Not much CC, but a lot of totems. You've never seen so many totems. Grace of Air, Windfury, Wrath of Air and Totem of Wrath all down at once. Shockapalooza, man, it was beautiful. My shoulders didn't drop, though. Totem of Wrath increased both chance to hit and critically hit with spells by 3% which is especially nice for caster DPS groups - I've heard shamans embrace it with love and claim that it's a worthless 41 point talent, I'll leave that kind of value judgment up to you. Personally, if you're going elemental I can't imagine why you wouldn't take it.
The 41 point enhancement talent is Shamanistic Rage. It's an astonishingly nice talent, made even better by the recent patch. The combination of damage reduction (a flat 30% off of the damage you take) and mana regeneration means this talent can help your steady production of damage in a fight rather enormously. Combined with the mana cost reduction of the lower-tier shamanistic focus, you'll find yourself quite able to produce steady DPS without panicking about running out of mana.
However, as someone who loves enhancement to death as a talent tree, I have to admit: good as it is, Shamanistic Rage isn't the best 41 point talent. Neither is Wrath of Air. No, the best 41 point talent in any shaman tree is Earth Shield. Oh, it's sublime, really. Used in PvE, it can make tank healing so much easier. Used in PvP, it can make killing a shaman intensely frustrating. I've kited rogues around and around forever using healing stream, ES and nature's swiftness to throw an instant healing wave on myself. ES benefits from your +heal when you cast it, so if you have trinkets that boost your +heal you should use them when you put it on, and if you have Wrath of Air you should be dropping it before cast if possible.
My first advice to a shaman who is approaching this level is to quest and save as much money as you can by avoiding the AH except to sell things. In fact, that would be my advice to almost any leveling character, even though I often succumb and go to the AH myself. If you can manage to avoid it, you'll end up with a lot more money, but I understand wanting to keep your gear as current as possible, and I know instances aren't always as friendly as they could be. Still, try and play it conservatively if at all possible. Training costs go up at this point, and you either just bought or are trying to buy your first land mount. (If you have a feeder 70 or two paying your way, feel free to ignore me here.)
As for zones to adventure in, if you didn't run Desolace or Dustwallow Marsh you should go clean out the higher-level quests in those zones before heading to Tanaris or Feralas. Between those two zones you'll be kept plenty busy, and also consider Azshara, an often overlooked zone with some interesting quest options (both Horde and Alliance have an extended questline in the Ruins of Eldarath, and there are faction specific quests in the zone as well). You'll be tackling Un'Goro and Felwood after Tanaris and Feralas, although if you're about level 48 and for some reason bogged down, you can always make a trip to the Searing Gorge, where the dark iron dwarves of Thorium Point have a good assortment of quests for you.
For an alternative, you can instead finish the higher level content of the Swamp of Sorrows and then strike out for the Blasted Lands, using the Searing Gorge as a supplementary quest hub. I'd suggest running all of these zones, taking breaks from one continent when it starts to get wearying. It depends on your likes, dislikes and tolerances, but I grow to hate a zone if I spend too much time in it. Also, don't forget the Hinterlands, especially not if you're Horde. The quest hub at Revantusk, in my opinion, offers superior quests and rewards than the corresponding Alliance hub at Aerie Peak, but either faction should spend some time here before heading north to the Plaguelands or off to Winterspring. If for some reason you can't hit level 58 in these last three zones, you still have Silithus to explore: you'll probably want to go there anyway just to get your cooking up to 300 if fishing is taking a long time to level. I personally dislike Silithus, but there are a lot of quests there. LIkewise, there's always the Burning Steppes if you're bogged down in other zones and need a quest hub to push you over. I find both Silithus and the Steppes somewhat unrewarding now that you're not likely to be doing much with those big instances in the zones, but at least the Steppes offers you the hope of a few BRD runs.
By this point you should easily be level 50. This means one thing: wanton carnality.
Oh, right, shaman quest. Sorry. Lost my place in the notes there. At level 50 both Horde and Alliance shamans are told to go speak with batty ol' Bath'rah the Windwatcher, tormentor of level 30 - 40 warriors and all around high level shaman. Bath'rah, after forcing you to provide him with a rather trivial test of prowess, will send you off to the delightful Plaguelands to gather the materials for a Spirit Totem. Strangely enough, even though Bath'rah is obviously insane and enjoys making you waste your time, the Spirit Totem doesn't work, and so Bath'rah sends you to the Swamp of Sorrows to kill his fellow trolls and collect feathers from their corpses. This achieved, at last Bath'rah is satisfied and goes off to take a nap, but not before offering you various rewards. If you're elemental, you may be tempted by the Azurite Fists. The Wildstaff is nice, but most melee shamans will by this point be dual wielding, and so I usually take the Enamored Water Spirit, as I'm usually low on trinkets around this level anyway.
The first dungeon you'll probably run in this level range is Zul'Farrak. All I can really say is, get used to killing trolls. Lots and lots of trolls. The standout drop for a shaman is the Gahz'rilla Scale Armor. If you're enhance, Ripsaw is the perfect speed for you. If you're not picky about wearing leather and/or cloth, there's lots of caster/healer drops in here as well. After ZF, head to Desolace and explore Maraudon, one of my favorite instances, if crazily long. Do the quest The Pariah's Instructions for a nice trinket, and I can now recommend the Infernal Trickster's Leggings for enhancement shamans with the change to hit rating instead of bow skill rating. The Blade of Eternal Darkness drops here if you get lucky. After Mara, you'll be heading back to the Swamp of Sorrows to the Temple of Atal'Hakkar, where (surprise!) you'll be killing more trolls. I apologize in advance, troll shamans. However, there's compensation for the slaughter of so many trolls packed into this instance. For those of us shamans who aren't trolls, kill with glee and loot away. (I actually left out several other drops that are good for a shaman in here, ST is just a nice stop for a level 50 shammy.) Finally, with the change to leveling, you'll probably stop in BRD a few times before getting serious about hitting Outland. It's a shame, as I really like some of the 57 - 60 instances like LBRS and Strat, but getting a group for them can be really tough now. I won't even try and pick out a standout item for a shaman in here, there are over 130 drops in here, you'll find something you can use.
At this point, you should be ready for Outland. Next time, we finish off the leveling guild with the march to level 70, and after that, I get back to talking elemental spec.