Leveling builds:
Shaman/Sent to lvl 17
Doesn't really matter what the 3rd spec is, could go with druid for a tiny boost in dps if you want or even warden for the instant cast HoT for extra survivability. But shaman/sent is all you need and should be one of the fastest ways to start out.
Glacial Shield when it's up. Bind Healing Breath on something easy to hit like your mouse thumb button or something and just heal with that. There's not much, if anything, that can kill you before that spell refreshes every 8 secs =P
Respec at lvl 18
This is the earliest you can switch to the farming build, but it won't be ideal until lvl 24 when you can get Even Justice for spammable aoe while Soul Drain is on cool down. If Shaman leveling is going fast you might want to wait until lvl 24.
Farming build at lvl 24
How it works:
Every little bit of damage you do will heal you with the Salvation buff up. It's not a whole lot of healing at once, but should be more than enough to keep you up through 2-4 mobs at the same time. Soul Drain with crits is nearly a full heal if you did it on 4 mobs at once.
Every life-based damaging ability you land will give you a conviction (up to 4) that you can use to power instant heal Doctrines. Both Salvation and Doctrine heals are boosted by Mien of Honor.
Vex also heals you for 90% of the damage done, plus another 7.5% from Salvation. Doctrine of Bliss is what you use if you pulled too many for Salvation and Vex to heal while Soul Drain is on CD.
Purpose gives mana back on melee hits when you get low. Aggressive Renewal is extra mana if Purpose isn't enough to keep you topped off. Ageless Ice is the same spell as Purpose when you unlock it in Shaman. Between these 3 you should never be OOM.
Soul Drain is a crazy powerful aoe, but it's point blank around you and only works if you have more than one mob. It does jack **** if you are only killing one target. It does the most damage when you have 4 mobs around you.
Spell Rotation:
You start off by Vexing as many targets as you want to farm (start low until you get the hang of it and know mob abilities. By lvl 50 you might be pulling 5-8 at once). Avoid ranged mobs unless you have something to LoS them around. When they gather around, Soul Drain then Even Justice until they are all dead. If it's just a single mob left, use Strike of Judgment. That's all there is to it.
Farming Build at lvl 50
Doesn't really matter how you get there. Finish the Justicar line first if you want better survivability or go Shaman if you want higher dps. Jolt and Rage of the North are both spells you'll want to get ASAP though and Battle Charge really speeds things up.
Gear should focus on crit and spell power and the highest dps caster 2Hs you can find.
Macros are below. Just delete the ones you don't have yet and keep adding abilities as you unlock them. The 2nd AoE macro is just there if you run into mobs that interrupt a lot or pulled too many to easily Soul Drain without casting knockback.
AoE macro #1:
#show Even Justice
suppressmacrofailures
cast Rage of the North
cast Jolt
cast Glory of the Chosen
cast Fated Blow
cast Soul Drain
cast Strike of the Maelstrom
cast Even Justice
AoE macro #2:
#show Even Justice
suppressmacrofailures
cast Rage of the North
cast Jolt
cast Glory of the Chosen
cast Fated Blow
cast Strike of the Maelstrom
cast Even Justice
Single target macro:
#show Strike of Judgment
suppressmacrofailures
cast Jolt
cast Glory of the Chosen
cast Fated Blow
cast Sanction Heretic
cast Strike of the Maelstrom
cast Lightning Hammer
cast Massive Blow
cast Sovereignty
cast Bolt of Radiance
cast Strike of Judgment