Due to popular demand, I'm going to talk about a Shaman leveling build, specifically the one I chose in getting to 60. After 60, due to itemization, you have a lot more options.
The following guide is what worked for me. It assumes no respeccing, so you'll have some talents that contradict each other - shield spec, 2h, and dual-wield. As with any guide, it may not be the best for your particular playstyle. It's just a suggestion for newer players on talents they can use to help level quickly.
While leveling up, you really want to maximize damage, as a paladin does with their retribution tree. You could level up as elemental or restoration, but expect a long long grind to 60.
Enhancement is truly where it's at. Everything in this tree is geared to either increasing the damage you do, or reducing the damage you take. When leveling up, these are pretty important.
You should pick your gear accordingly as well. Strength increases damage and how much you block with a shield. Stamina increases hitpoints, Agility increases crit rate, and Int increases mana and spell crits. I'd place importance on stats in that order, but that's personal opinion.
Read on for the entire build.
As a result, we're going to only look at the Enhancement tree.
Tier 1: Levels 10-14
Shield Specialization - 5 points. Even at level 70, the 5% mana increase is going to equal 300-400 mana, enough for 1 extra lightning cast. Compare that to 5% increase in block and 25% increase to how much you block? No brainer. Shield Spec rules, even at high levels.
Tier 2: Levels 15-19
Thundering Strikes - 5 points. You want to crit as often as possible.
Tier 3: Level 20
Two-handed axes and maces - 1 point. If you want to really do a lot of damage at the lower levels, take this. I keep it even at high-level, as there are some nice 2-handers out there for resto/enhancement too.
Tier 2 and 3: Levels 21-24
Improved Ghost Wolf - 2 points. This is your get-out-of-jail card. A fast transform can let you flee a fight with your life. I lose it at 60, but for leveling it's great.
Enhancing Totems - 2 points. 15% increase to your two primary buffing totems. This means higher damage, more crits, better dodging.
Tier 4: Levels 25-29
Flurry - 5 points. Faster attacks? YES PLEASE!
Tier 5: Levels 30-33
Spirit Weapons - 1 point. Yay for parry! The 15% threat reduction is great for grouping. And it's the pre-requisite for dual-wield!
Elemental Weapons - 3 points. 40% increase to Windfury. Windfury is your bread and butter. Once you get it, you put it on your weapon and never take it off. Some folks like Rockbiter. Let em - damage works out about the same in the end, but Windfury attacks still let you get procs on an important talent later on. [EDIT: Changed Windfury to Elemental. I must've had the buff on my mind]
Tier 3 - Level 34
Anticipation - 1 point. I hate that you're stuck with 1 loose point at level 34. 1% dodge is good, much better than 2% armor, so I place the point here
Tier 5 - Levels 35-39
Weapon Mastery - 5 points. 10% extra damage with all weapons. 'Nuff said.
Tier 6 - Level 40
Dual Wield - 1 point. Are 2 weapons really better than one? I played with both, and while I think the end damage is comparable, it's more fun to watch your shammy attack with 2 weapons.
So here's what your talent tree should look like at 40: http://www.wowhead.com/?talent=uZVVbdq0sVz
at 40, you can swap out to chain armor and have 2 weapons. It's also time to get a mount. You could respec at 40, removing imp ghost wolf and 2-handed weapons, as you now hopefully have a mount and definitely have dual-wield. I prefer to keep this all the way to 70 though, so we'll continue.
Go get your chain, still focusing on str/sta/agi/int, and get 2 weapons. For maximum Windfury damage, get the slowest, highest top-end damaging weapons you can find.
Let's move on to 40-60, shall we?
Tier 6 - Levels 41-44
Stormstrike - 1 point. Instant attacks, and then increases your post-attack shock by 20%. YAY! More damage!
Dual Weapon Specialization - 3 points. This helps a lot in hitting with your off-hand. More hits = more damage
Tier 7 - Levels 45-49
Unleashed Rage - 5 points. 10% AP increase for you and party members after a critical strike. It's not much to start, but you can never say no to more damage
Tier 8 - Level 50
Shamanistic Rage - 1 point. Mana regen from hitting things? Oh yes! Now, this relies on high attack power, so to maximize mana regen, drop your Strength of Earth totem before going into a rage. If you're in a party and have been battleshouted by the warrior, even better.
Elemental Tier 1 - Levels 51-60
What?! But Paul, you said this was an Enhancement Build!! Yeah, I know, but you want more damage, and you want it cheaper and faster, right? Elemental is a great side-arm to enhancement.
Convection - 5 points. More mana-efficient offensive spells.
Concussion - 5 points. More damaging offensive spells.
And now the push from 60 to 70. It's interesting, because the last 10 levels give you a couple of options. Help your healing and get cheaper totems, or fill out your enhancement tree:
Restoration Tier 1 - Levels 61-65
Tidal Focus - 5 points. Cheaper heals
Restoration Tier 2 - Levels 66-70
Totemic Focus - 5 points. Cheaper totems. You use totems a lot, so this is great.
So your build looks like this: http://www.wowhead.com/?talent=hEZVVbdq0sVuqoV0x
Enhancement Fill-out - Levels 61-70
Tier 6 - Mental Quickness - 3 points. Reduce the cost of your shocks even further!
Tier 2 - Improved Lightning Shield - 3 points. Do some damage back!
Tier 3 - Anticipation - 4 points. Max out that dodge
In this case, your build looks like this: http://www.wowhead.com/?talent=uEZVVfdE0sAuqo
So there you have it, 1-70 as an Enhancement shammy, with a couple of different possibilities towards the end. Let me know what you think.