From my experience, haste won't do much for you unless your other stats are pretty good. If your mana regen is low, you'll have fast casts, but then you'll run out of mana (oom) and have to stop casting to regen.
While I was learning to heal I gemmed for anything that was low. Now, it's pretty much all Spell Power. My armory is:
http://us.wowarmory.com/character-sh...ra&cn=Galurana
My main spells are Regrowth, Rejuv and Nourish. I haven't used Healing Touch in I don't know how long and tranquility might get used once every other month. Maybe.
I use Healbot and Quartz. Healbot is set up to show my HoTs on the bars so I know easily when to recast and don't waste mana. My full spec is set up for both tank and raid healing. I didn't get Nature's Swiftness because when I did have it, I didn't use it. I find Swiftmend works just as well.
The main thing is, to try to keep your stats balanced so you have a nice fast GCD and aren't shorting yourself on mana or spellpower.
Good luck!