like the previous poster said wow teaches you the mechanics slowly.
shaman in a nutshell.
Shaman drop 4 different totems. earth, fire, water, air.
each totem has different choices for types of buffs/resistances for yourself and party members. (nothing forces you to drop any if you don't want to.)
They are not all party buff specific either. You can use Sentry Totem to spy or have visibility in different areas.
Stoneclaw Totem to pull mobs off you if you need to make a hasty escape.
you have DPS totems like Magma Totem Searing Totem
and who can forget our big buddies... Earth Elemental Totem Fire Elemental Totem
weapon enchants are just another self buff
depending on spec we are melee DPS or Range DPS. our healing spec is generally raid healing but i do have a convincing tank heal arguement spec i can show you.
we bring multiple buffs and Heroic Presence. we have the all impressive heroism talent as well.
I have levelled (to 80) a paladin, hunter, shaman, death knight and through them all the shaman was and is my favorite. Blizzard has done a good job of totem management and has some great changes coming in cataclysm.
Shaman don't need a build up mechanic to use any abilities. just plain old mana. No rage build up. No death knight runes.. no combo points... etc. If you can keep your mana up your still a threat.
All classes bring some sort of diversity and play style. what some may think difficult may make total sense to you and fit your play style. It takes all kinds to mold azeroth.