New 60 priest needs help with spell deranking

[N3oN123]

How should I derank my spells? What rank should they be? Will I ever need my max rank spells? I played a lock in vanilla retail and I didn't have to do any of this. Sorry for the noob questions!

[Garfunkel]

Get Luna Uniftframes. It has a mouse-over healing function. You can assign six spells to be cast, depending whether you use LMB or RMB and either shift, alt or ctrl. The six spells that I have in it are max rank Renew, max rank PWS, max rank Flash Heal, max rank Greater Heal, Heal rank 4 and Heal rank 1. Currently my Heal(1) heals for about ~ 500 and Heal(4) heals for about ~1k. In my raiding environment, those are pretty much spot on.

Now downranking depends on few things: how much +heal you got and how hard is your tank getting hit. You can only be certain of the first thing and you'll learn the second with experience. In a random 5-man pug, just observe how much damage the tank is getting and that will give you your answer on how much to downrank. In a raid, you're not healing a tank by yourself, so you have to judge which ranks are sufficient to keep you healing significant amount (there is no point in spending 2.5 seconds to cast a spell worth only 200 hp) while not taking you OOM too fast.

Note that being OOM is not an excuse when raiding, you should stack up on mana pots and runes and use mana oils and mp5 food buffs while progressing/gearing and for emergencies of course.

[Forcerius]

How should I derank my spells? What rank should they be? Will I ever need my max rank spells? I played a lock in vanilla retail and I didn't have to do any of this. Sorry for the noob questions!

You can downrank heals so you don't overheal too much like the other person said. But you can also downrank SWP and renew for PVP. Rank 1 SWP is good if you need to stop a rogue but you're oom, or for blackout procs, or for stacking 5 debuffs. Down ranking renew is good if you have someone spam dispelling or purging you. Its also good to do with fear since you don't need to use the highest level fear for only 1 target. Although, I don't downrank that because I always forget and I'm 99% out of binds, even with shift and ctrl modifiers. Guess I should make room since every bit of mana is important in PVP.