to get it started:
@self <spell name> Cast a spell on yourself.
@focus <spell name> Cast a spell the focused target.
@focustarget <spell name> Cast a spell at a target of a focused target.
@lasttarget <spell name> Cast a spell on the last target before your current target.
@targettarget <spell name> Cast a spell on your target's target.
@pet <spell name> Cast a spell on your primary pet.
@mark # <spell name> Cast a spell on the creature or player marked with # (only usable in group/raid).
from http://www.rifthead.com/guides/macros.

The last one is pretty helpful. It target a specific raid icon.