I'd put points in this order:
HOLY TREE--
5 into Spiritual Focus - Priceless. Lets you get heals off even while being ***-^&*#ed by 20 monsters at once.
5 into Illumination - See below.
1 into Divine Favor - Coupled with Illumination, this gives you a HUGE cure every two minutes for only 17 Mana. That's a 260 HP cure at lvl 20. A 450 HP cure at lvl 22...and so on.
Unless you wanna go for Holy Shock, there isn't much else in this tree worthwhile. Maybe Improved Holy Light if you feel like it.
PROTECTION TREE-
Here I'd make a beeline for Blessing of Sanctuary. Personally I'd pick the Retribution tree for Consecration to get threat and tank in instances, but the Protection Tree isn't bad either.
5 into Redoubt or Improved Devotion Aura - I'd pick Imp. Devotion as I'd rather not put my faith into the enemy's critical strike chance. I've heard Redoubt coupled with Holy Shield makes for an amazing defensive tactic, but I dunno.
5 into Toughness, Redoubt, or Imp. Devotion - Toughness is nice. Need this for Sanctuary and Holy Shield.
1 into Blessing of Sanctuary - Lowers the damage done to you by quite a bit. Seems a but situational, as Blessing of Wisdom is damn nice as well, but still a good Blessing.
5 into Shield Specialization - Need this for holy shield.
4 into Toughness, Redoubt, or Imp. Devotion - If you're going this way might as well get the third one.
1 into Holy Shield - Amazing skill, or so I've heard.
This is the only build I can really see effective if you don't wanna go retribution. Personally I think there isn't any point being so defensively aspected if you can't keep the threat on you...which is damn hard without some DPS or Consecration or something. But this is a defensive build...