Tier 1 • Tier 2 • Tier 3 • Tier 4 • Tier 5
Here's another of those "features" I've been trying to focus on lately. What I'm going to do is go over all the talents in the shaman talent trees, and write what I know about each of them, and say whether you should or shouldn't get them, and so on.
But I'm going to do it a bit differently than you'd expect. I'm going to go tier-by-tier, doing all 3 talent trees at the same time. Which means that this will be a 9-part series.
I should also mention that I know the most about the Elemental tree, slightly less about the Resto tree, and not a lot about the Enhance tree. Remember that when considering my advice.
I'm also using a 5-star (bloodlust icon) rating system. 5 = great, 1 = bad.
Elemental
Convection 
Reduces the mana cost of your Shock, Lightning Bolt and Chain Lightning spells by 2/4/6/8/10%.
Essential for any Elemental build, and decent for an Enhance build. The benefits should be obvious: less mana = more longevity. And longevity is something that Elemental and Enhancement shamans can have a hard time with.
Concussion Increases the damage done by your Lightning Bolt, Chain Lightning and Shock spells by 1/2/3/4/5%.
Another essential Elemental talent. It may not seem like much, but you'd be a fool not to take it for an Elemental build. It's also pretty nice for Enhancement; a Concussion-enhanced Earth Shock on an enemy under the effects of Stormstrike will do some pretty decent damage.
Enhancement
Ancestral Knowledge Increases your maximum mana by 1/2/3/4/5%.
This talent kinda sucks. I would encourage you to skip it, but your other option is even worse. It sucks the most as an Enhance talent, due to the fact that Enhance shamans have very small mana pools. You'll be lucky if that 5% gives you enough mana for an extra Earth Shock. If you need to go deeper into the Enhance tree, get this talent. If you don't, avoid it.
Shield Specialization Increases your chance to block attacks with a shield by 1/2/3/4/5% and increases the amount blocked by 5/10/15/20/25%.
Probably the worst shaman talent available. It's an obsolete holdover from a bygone era, like a vestigial tail. Shamans don't tank anymore (and never really did to begin with).
When you're leveling (as Enhance), you should be using a 2H weapon until you get Dual Wield. If you need to get deeper into Enhance, put points into Ancestral Knowledge, which sucks slightly less than Shield Spec does.
Restoration
Improved Healing Wave Reduces the casting time of your Healing Wave spell by .1/.2/.3/.4/.5 sec.
If you're going to be a healer, this is an essential talent to have. It lets you cast your big, mana-efficient heal faster, which means better survivability for you and your group. And Healing Wave has a lot of synergy with other talents, like Healing Way and Ancestral Healing. A nice side-effect is that it makes your Rank 1 HW cast in just one second, so you can quickly stack Healing Way on your tank and keep it up pretty much as long as you want.
If you're just going after talents in other tiers (like Elemental shamans usually do) it's usually better to go with Imp. HW than Tidal Focus. You probably won't be healing enough for the mana decrease of TF to make much of a difference, but everyone loves having a huge slightly-faster heal when things get rough.
Tidal Focus Reduces the mana cost of your healing spells by 1/2/3/4/5%.
Essential for healers. It's not a huge decrease, but as I mentioned before, getting every little bit of mana efficiency for your primary role is key.
Well, that's Tier 1. Tune in next time (whenever the hell that is) for Tier 2.
