Elemental Shaman is a ranged DPS that also provides support with totem buffs, Bloodlust, and [Elemental Oath] that increases the party or raid spell critical strike chance by 5%.

Rotation for Elemental Shaman Wotlk

Elemental Shaman Priorities

Flame Shock (Keep debuff up) > Lava Burst > Lightning Bolt > keep Lightning Shield up > Thunderstorm for mana

Tips

For AOE use Chain Lightning and magma totem.

For totems use Strength of Earth (earth), Totem of Wrath (fire), Mana Spring Totem (water), Wrath of Air Totem (air). If there are more shamans totems should be decided to not waste buffs.

At the end of a cast an instant spell can be cast without occurring GCD, this is true for every cast/instant sequence, should be used to maximize DPS.

Use CDs when there is barely any movement or crowd control effects to maximize DPS, the best way to do this is by knowing the fights.