The main thing that most players look at is the racial abilities

Races - There are four different races that can be Shamans: Orcs, Trolls, Tauren, and Draenei with the Burning Crusade expansion. Without the Silkroad gold expansion, you will be limited to the three original races that could be shamans, all of which are of the horde faction. Choosing your race can be a hard choice for some players.

If you wish you be an Alliance shaman, your only choice is Draenei, making it a simple choice. As for Horde, you should ultimately pick a race you enjoy. Starting abilities have very little to do with the game further in; once you approach level 20-25, your abilities depend more on your gear. Here is the ability score of level 1 shaman with no gear, based on race.

The main thing that most players look at is the racial abilities of each of the races. Racial abilities can save a player from an encounter, or they can make his time to achieve a goal that much faster.

Blood Fury - There are 3 different versions of this racial ability. The shaman version when activated, gives (Level*4) +2= attack power and (Level *2)+3= spell damage/healing. This ability lasts 15 seconds and has a two minute cool down. This is a very good racial ability for Shamans. It helps both melee base shamans and caster base shamans.

The two minute cool down on this allows for pretty constant use, and makes it so that you do not have to save it for an upcoming boss.