As far as specs go:
http://wow.allakhazam.com/db/class.html?wclass=2;mid=1199225539229237521;page=1;howmany=50#m1199294416120734722
That's my raid/heroics spec.
Spell Damage:
Most of your spell damage should come from your weapon. Pick up a Crystalforged Sword off the AH or a Continuum Blade from the quartermaster in Caverns of Time and throw a +40 Spell Damage enchant on it. After that you can upgrade to the Gladiator's Gavel (best gotten during an AV weekend, should take you 2 - 3 days of pure PVPing to get it), which should also get a +40 Spell Damage enchant.
If you find some tanking gear (meaning it has + Defense/Dodge/Parry/Block Rating on it as well) with spell damage you should pick that up as well (take a look at the Pally T4 set to know what I'm talking about, or Boots of the Righteous Path). Try not to pick up gear with Parry / Hit Rating or Expertise though, you can't afford to.
^^^ This is more of a general rule until you get your feet on the ground and know what you're doing.
**Edit** Try to avoid the tanking gear that drops from Heroics for the most part (such as Eaglecrest Warboots). They are VERY MUCH geared for a Warrior and NOT a Pally.
Melee Stats:
Parry and Dodge "cost" more to get more avoidance on an item than Shield Block Rating. What does that mean? It takes less Shield Block rating to get uncrushable (which is priority #1 as a Pally tank) than mixing Dodge and Parry. Your first priority is to get uncrushable while Holy Shield is up. Using this macro (After you throw up Holy Shield) will tell you how close you are:
/script DEFAULT_CHAT_FRAME:AddMessage("Need 102.4 combined avoidance. Currently at:",0.8,0.8,1)
/script DEFAULT_CHAT_FRAME:AddMessage(GetDodgeChance()+GetBlockChance()+GetParryChance()+5+(GetCombatRating(CR_DEFENSE_SKILL)*150/355 + 20)*0.04,1,0.5,0)
Strength is meaningless for a Paladin tank. We use Spell Damage for threat, warriors use Strength.
If you need a gem to hit uncrushable, then by all means DO IT! But other than that, stock up on Solid Stars of Elune and use them. Socket bonuses don;t mean much.
Check the sticky entitled "Defense and Mitigation" for more info
Edited, Dec 24th 2012 4:32am by Deevious