From here, if you do both starting zones and are done with Grizzly Hills and Dragonblight, it's very possible to be level 76/77, especially if you were rested for a good portion of that time. If not, Zul'Drak will get you the rest of the way and of course has an excellent series of quests for you including the successor to the Ring of Blood with rewards that can easily take you fom 75 until you start running instances at 80 to prepare for heroics/raiding. After finishing Zul'Drak you'll have your choice of Sholozar, Icecrown and Storm Peaks to explore. I suggest doing Sholozar first because it's good XP with all the various Kill 15 of X quests from Nesingwary, combined with the Avatar of Freya questlines and the Oracle/Frenzyheart quests. Whether you choose Icecrown or Storm Peaks next, you'll ding 80 before you finish: I'd suggest hitting Storm Peaks first to get a start on the Sons of Hodir rep grind, as you can't wear a tabard with those guys. Icecrown has several questlines (do the Ebon Blade and Argent Crusade ones as soon as you can to get the zone's phasing to open up flight points/quest and repair hubs for you) that will net you gold and reputation in order to pick up gear and head enchants from the Ebon Blade and Argent Crusade.
In my opinion leaving Storm Peaks and Icecrown for after Sholozar means that all that rep grinding you have to do anyway turns into more gold than it otherwise would, but you can run these three zones in whatever order you like and easily go from 77 to 80 before you're done with them.
I'll repeat our gear guides here for anyone looking for that information: we covered Borean and Howling Fjord and their instances here, Dragonblight and the AN instance here, Grizzly Hills, Zul'Drak and the two troll instances here, and wrapped up instance loot in two posts here and here. This actually leaves quest loot from Sholozar, Icecrown and Storm Peaks (some of which is actually very good for leveling/running your first 80 instances). We can't hope to cover all possible drops in those three zones, but here are some highlights.
In Icecrown, there are quite a few blue quest rewards to keep an eye out for (and one or two greens that are worth considering as well) - one green I will point out to enhancement shamans who took me to task this week (and rightly so) over not being excited about expertise on the new Unleashed Rage coming in 3.1, which I really should have been. It's the Crusader's Locket, a strange trinket available from the opening quests to get the Argent Dawn flight point into Icecrown to open up. Obviously, the 106 AP is nice, but the proc on it will reduce your chance to be dodged/parried by 7.6% or so when it is up. Now, nobody wants their expertise to be proc based. But when you consider the relative paucity of expertise on mail gear, this trinket becomes one you might want to hold on to until you can reduced dodges by the 6.5% you need. Also in the spirit of expertise, there's the leather Shoulderpads of Fleshwerks, which my draenei is still wearing in Naxx partially because nothing will drop, and partially for the expertise (in fact, I have more exp leather than those on).
The Basic Chemistry quest given by both Horde and Alliance DK quest givers offers three rings that shamans might be interested in. The Fate of Bloodbane quest, similarly accessible, offers a physical DPS cloak, a crit/spell power cloak, and an MP5/ppell power cloak. The Admiral Revealed (spoiler warning if you haven't gotten that far yet) offers several socketed necks for shamans to choose from, just ignore the tanking one. This caster shield is available by helping a Banshee get some Revenge. The quest The Last Line of Defense has a crit/spell power trinket, an MP/5 and spell power trinket, and a haste/AP trinket.
Caster mail is available through quests as well, as is a decent caster weapon. Enhancement can pick up a nice set of wrists or a solid helmet as well as a socketed ring.
In the Storm Peaks, shamans have a quest (Alliance and Horde flavors) that comes with a variety of ring flavors. While almost certainly intended for tanks this ring must be considered by any enhancement shaman desperate for expertise. (If you're really, really hurting, there's also this green mace.) Caster shamans can pick up a set of gloves and enhancement shamans a pair of pants as well.
Next week, we'll cover Sholozar Basin and discuss new abilities you gain as you level, from Lava Burst to Hex. Now if you'll excuse me I have to go beat up on some Gorlocs.