Here is my 20/0/41 retnub loladin build for soloing. The idea is that the faster you kill, the faster you level.
It's based around judging crusader, then casting seal of command, judging it and recasting it every time it comes up. Plus throwing in a crusader strike here and there for extra damage. I also took the holy talents I thought would give me the best healing for the points spent, so I can keep myself up.
I'm trying to collect as much "of the sorcerer" gear as I can for intelligence, stamina and plus spell damage and healing. I'm not trying to do a ton of melee damage here, but to boost my holy damage as much as I can. The downside of this build is that if you try, you can run yourself out of mana really fast, but it makes hunting undead or demons pretty fun.
I also took herbalism and alchemy as my main professions, so I can make the mana potions I'll be using a lot myself.
I'm considering speccing 31/0/30
this way with holy shock and vengeance for better healing with similar damage so I can be more useful to groups, but I haven't played with that build so I don't know how good it is in practice.