Greater Heal Use when target needs a large heal, but it isn't urgent. This is mana efficient and should be your primary heal. The main healing spells you'll use are: Heal Use when target needs a heal. Heal Rotation A healer is a dynamic, reaction-based role and so the 'rotation' is more-so a toolbox of spells of multiple ranks to be used as needed. As a raid healer, you'll need to find a balance between keeping your raid healthy and not running out of mana. You'll want to keep Renew active on important targets taking damage, and to use Power Word: Shield and Flash Heal on urgent targets. When healing a raid, you'll want to utilize Prayer of Healing when your party is taking constant AoE damage. Using lower ranks of a spell is a good way to be more precise with mana spending and healing output. A healer is a dynamic, reaction-based role and so the 'rotation' is more-so a toolbox of spells of multiple ranks to be used as needed.
This is a quick reference-style guide to the healing 'rotation' for Priests, covering the basics of which spells and ranks should be used and when.