I'm not sure whether to put this on the offspec forum, or in the dungeons thread, or even whether to make a new thread in this forum, but here goes.
Halp! 
Most of the time Holy paladin healing seems Really Easy, but every now and then everything goes completely to hell in the space of like four to six GCDs, and I don't know what I did wrong, or what I could have done better.
This is my armory:
http://us.battle.net/wow/en/character/kirin%20tor/caelus/advanced(Shame: I need to enchant some of the recent upgrades. However, I think my tactical mistakes are outweighing this.)
I tend to save my holy power in anticipation of bursty healing needs, and try to use mostly Holy Shock and Holy Light. However, when things DO start to go south, I've already spent my Holy Power on someone, and am watching my group wither while I am casting Holy Radiance or Holy Light.
I was having a lot of trouble last night with the Queen Azshara fight in the Well of Eternity -- I had three melee, so Holy Radiance was pretty easy to get on them, but I was still generally watching the group melt. (Perhaps I should gem for haste/mastery rather than spirit? I'd assumed that I needed all the spirit I could get.) Are there any particular tricks to that fight, or was I just failing hard at healing? (It felt like it.) Next time I'll mark a kill order better, but I really feel like I have a lot of room to improve
my play, but no clue as to how. I'll be really grateful for any advice that you guys might have.