hey -i have a lot of raid videos in my channel
www.twitch.tv/scrogglez - all resto and I rank top 20 on World of Logs nightly in raids - What I try to do is :
Riptide off CD on tanks or whoever will be tanking dmg - Voodoo ppl on gara'jal etc
Chain heal when AOE is incoming
Zerker + Elemastery + Tide = Amazing
Link + ascendance mixed with healing rain is amazing as well.
As for secondary stats Haste to lowest soft cap
50% mastery
Rest in crit
Don't drop any spirit
UE + healing Rain always - never w/out !!!
Drop your healing stream 24/7 on cd and if you run call of elements ,use it right after you drop a stream to max the downtime on the cd.
There is a lot to learning shaman but they are VERY strong healing atm in 10 and 25m. Good luck