Mp/5s is the third stat that any resto druid should look out for. As a resto druid, you will seldom find yourself outside the FSR rule – which means that mp5 (which always works) is a good way to regen mana. The best way to regen mana is in fact MP/5s (but Spirit wins overal...
Currently, the best gems for resto shaman are red and yellow. Blue gives us the least benefit. The gem might have some benefit if put in a secondary (or duplicate helm) and used as part of a spell haste set. However, yellow gems give spell haste so the meta might work against gems ...
When you have to move (you do a lot in cata fights) press swd.Swd gives you 12% of your mana pool back, disperse is 6% per sec, hymm is the worst mana/sec at 3%. A larger mana pool will help out, but a fully geared spriest has like 15k-20k more mana than one just entering...