The Spirit Realm

Call of the Wild - Your group will thank you when your cleric dies

Finish off Virulent Paralysis - It'll never cease to be fun and you'll lose count on how many times it saved your life within the first couple weeks of maxing it out, especially if you solo tough content.

Combat Agility/Lightning Reflexes - Again, you'll lose count of how many times it'll save your life

Ancestral Guard - Instant click Group HoT. Enough said

Start on your Healing Adepts - It'll really help you fill a roll as healer in groups

Honourable mentions would be Spirit Channeling and Gift of Mana. But I'd recommend concentrating on working on the others first.

As mentioned before, Spirit Call (dogdogs) is a pretty decent AA. However, you should just grab the first rank of this, as it will give you three dogdogs for a minute. The dogs that are summoned are our lvl 61 pets (I think lvl 67 spell, our highest lvl pet anyway). The DPS isn't too crazy, but you can call them back every 12 minutes and is a pretty stable amount of damage for no mana every once in a while.

And yes, Spiritual Channeling does own, but one thing these guys forgot to mention is that if you're spam healing the MT and don't have Spell Casting Sub. or Epic 1.5, it generates a lot of agro. I know from personal experience, and just remember to watch yourself and try not to be Superman cause you will get summoned and beat on