No matter what your class, always so up on time and prepared. Have morale, power, and WPDF pots as well as 30 minute tokens. It is also appropiate to have 10 minute food for boss fights and battle/warding scrolls.
Champions generally fill two roles in a raid: DPS or off-tank. The raid leader will let you know which role you will be filling so you can be prepared.
DPS is the the easier of the two primary roles for a champ. The champion is expected to follow the raid assist in burning down a target. Champs are expected to control single target and AoE damage based on the situation and dynamicaly adjust if it changes. Champs should never break crowd control!
As with any DPS role, the champion is expected to manage DPS with aggro and power usage. Champions are also expected to manage their morale as best possible. If the mob is putting out AoE damage, champions should get out of range if their morale is dropping until they are healed up.
Champs may also be called upon to be a raid or melée assist. In this case the champ should know mob types and kill orders and work from low morale to high. Also they should click target rather than tab target!
Off Tank is a primary role that adds another dimension to the DPS role. An OT champ will be expected to switch from DPS to OT when called for. It is expected of an OT that they can hold the aggro of a mob while limiting the amount of damage being taken. This is often combined with effective secondry role function as well.
In a raid, in addition to the primary role as DPS or OT, champs are expected to fill a secondary role as well. I would call this role Mob Control. This is very distinct from Crowd Control! Champions will be called upon to remove corruptions and interrupt the inducions of mobs. It is important to know how to effectively clobber a target by watching for the induction ring as well as keeping enough fervor up to execute. Champions are also the last line of defense for the healers: if a mob or mobs come off of a tank, the champion should be ready to pick up the mob(s) and bring the back to the tank. The final part of mob control is contributing to keeping the mobs on the tank through the effective use of Ire.
Location:Expectations : Champs