Shocks and shock cooldown.

Your shocks are one of your most potent weapons in PvP, but only if you use them wisely. You might be able to win by spamming frostshock on your opponent, but don't count on it. Let's look at our available shocks:

Flame Shock - This shock does damage when it first hits and does further damage periodically over 12 seconds. The damage over time component is useful when you're fighting a rogue and don't want him to vanish and escape.

Earth Shock - Best against casters, this shock does damage up front but also acts as an interrupt. Earth Shock will interrupt spellcasting, and prevent any spell of that school being cast for 2 seconds.

Frost Shock - An iconic Shaman spell, Frost Shock does damage and slows the target for 8 seconds. Great for when you want to catch a fleeing opponent, or when you don't want to be caught.


The cooldown of each shock is 6 seconds, unless your talents include Reverberation in the Elemental tree (which at 5/5 points reduces cooldowns by 1 second). The tricky thing is that the cooldown is shared across all three shocks. In other words, if you cast Frost Shock on a mage, they will have a 6 second window where you can't interrupt any of their spells with Earth Shock. It also means that you have to be picky in choosing what spells to interrupt. Yes, you could cancel an Elemental Shaman's Lightning Bolt spell, but he'd still be able to cast a healing spell right afterwards. Knowing what spells each class has available will help you prioritize what to interrupt.

If you can, use your totems instead of shocks to keep the shock cooldown available. In the first example I gave, you could use an Earthbind Totem to slow the mage instead of a Frost Shock. In the second you could use a Grounding Totem to absorb that Lighting Bolt and have the Earth Shock available for the heal. You'll find that taking a more strategic approach to shocking will serve you better than gratuitous spamming.

Disease Cleansing Totem.

I am sick. In honor of my cold, let's talk about the Disease Cleansing Totem.



Casting Time: Instant.
Range: 20 yard radius.
Cost: 8% of base mana.
Duration: 2 minutes.
Totem type: Water.


Whenever there's more than one charge of disease debuffs spread onto your group, this will be your go-to totem. Using this totem is more mana efficient than using "Cure Disease" repeatedly, and frees you up to be doing other things in the meantime. As it's cast the totem will dispel one debuff from each member of the party, and will do so again every 5 seconds. This is a totem that doesn't get used very often, but in certain situations you'll be very glad you have it.

I am the Lorax, I speak for the trees.

Talent trees, that is! We shamans are a hybrid class, with the ability to fill many roles. Our choice of talents is what allows us to specialize in a particular area. The three talent trees are Elemental, Enhancement and Restoration. Although I have the most experience in Enhancement and Restoration, I'd like to take this time to discuss all three.

Elemental

The Elemental talents buff a shaman's offensive spellcasting ability. Although shocks also receive some loving in this tree, the Elemental Shaman's biggest tools will be the Lightning Bolt and Chain Lightning Bolt. There are 15 buffs to Lightning Bolt between the Elemental and Restoration trees, and when these are all applied the spell becomes a very powerful and mana-efficient damage dealer.

PVE shamans may choose to go all the way to the 41 point Elemental talent: Totem of Wrath. This fire totem grants all party members an additional 3% chance to hit and to critically hit with spells. Elemental shamans who focus on PVP often skip the Totem of Wrath in order to place 21 points into Restoration, which allows them to buy Nature's Swiftness.

Restoration
Restoration is all about healing. This tree reduces the casting time and mana costs of healing spells, and adds several interesting effects to the vanilla healing spells. An example of this is Healing Way, which adds an effect to the target of a Greater Healing spell that enhances following heals. Nature's Swiftness, at 21 points in Restoration is a very popular spell for all shamans. This talent makes the next nature spell, whether healing or damage, into an instant cast. Many PvP oriented shamans will skip the 41 point talent in their main tree to get Natures Swiftness instead.

Restoration is a popular choice for raiding shamans, and is a solid healing choice. My main complaint about the tree is that it lacks mana efficiency, causing me to consume many mana potions. Another drawback is that to get the most out of the tree requires a very large investment of talent points. When I'm wearing my healing hat I have no less than 50 points in Restoration, and I know shamans who spend even more.

Enhancement
Enhancement is the second of the damage trees. Where Elemental is about buffing magic damage, Enhancement focuses on increasing melee damage. In addition to the shaman's own damage, it also helps to buff melee-wielding party members. All shamans have the ability to use melee weapons and the spells that buff them, but Enhancement brings those abilities to their peak. These talents Enhance the weapon buffs such as Flametongue and Windfury, grant the ability to wield two-handed weapons or to dual wield and basically allow you to smash people in the face. Hard.

The downside to Enhancement in PvE is that the damage it deals out tends to be come in bursts, which combined with the class' lack of an aggro dump makes the enhancement shaman notorious for suddenly getting splattered in instances. In PvP the major disadvantage of this build is that it relies on getting close to an opponent and has no way to defeat crowd controlling abilities.

Conclusions
I hope that these brief descriptions give you an idea of the basics behind each of the talent trees. The idea's not to get into the intricacies of each build, but to give a frame of reference for any readers who are unfamiliar with shamans. From now on, if I were to whine about trying to pull off daily quests while specced Resto, you will know that I'm bemoaning my lack of damage potential while using a talent tree meant for healing.