World of Warcraft Insights takes a look at the shaman class. The shaman class can be one of the most versatile like the paladin class. As a shaman its not so much about build as it is what you want to be like. The three choices are caster, melee, healer, or (here's the best part) a combination of any two.

Caster - for this you want to go deep in the elemental tree while picking up a few out of the other two trees to max your damage and mana pool/regen

Melee - enhancement is your tree. Getting DW is your main goal to shoot for then choose what suits you best while pulling some out of elemental to help your burst dps from your shocks, as well as some out of the restoration tree to help your survivability.

Healer - just what it says though most likely you will be an off healer due to the lack of the big heals and the threat reduction. Here you will be mostly in the restoration tree while finishing in the elemental tree to help your heals

Hybrid - here choose any two of the above and go half way down both trees. You won't be as good at something as someone who sticks with just one but you will be more versatile just in case you have to quickly change your roll.

Shamans are better though of as a boost to what you are lacking due to the fact that you can find a different class that is better at anything the shaman does but the shaman can switch rolls at the drop of a hat. Also the totems they carry can help with just about any situation.