Quick 'n' Dirty Paladin Guide

[Texaporte]

John, Adam, and Lars have paladins who want to be heroic tanks, so I'll post a quick and dirty guide on how to be a paladin. Any other questions, or additional suggestions by Avri, are appreciated.

Talents
The standard tank spec is 0/53/18, though some of the points are negotiable.
Nyrrin's tank spec
Tex's tank spec

The must-haves in each tree, Nyrrin and I both have. These are the negotiable points:
1/1 Divine Sacrifice
2/2 Divine Guardian
3/3 Crusade

Crusade is the best threat/dps talent available... IF you're going up against Humanoids, Demons, Dragons, and Elementals (which is most of T7 and T9 content. In Ulduar and Ulduar only, Seals of the Pure edges it out). Meanwhile, if you're not a fan of DSac and DGuardian, you can choose to put those 3 talent points into Reckoning or Improved Hammer of Justice instead (which isn't bad if you're going to be a heroic tank). Seal of Command is just bad, and you shouldn't be using it as a tank. Heck, you shouldn't be using it as a ret paladin either, but that's another discussion.

Note that Nyrrin and I also only take 1/2 Spiritual Attunement. This is because 100% uptime divine plea and Blessing of Sanctuary cover the rest of the mana. If you're having huge mana troubles, stop consecrating or don't try to tank Vezax (*shakefist*)

Rotation
Assuming you have 1/2 Improved Judgement (which you should), your rotation consists of 3 abilities with "9"-second cooldowns (some of them actually have 8, but that doesn't divide well with the 1.5 second global cooldown) and 2 abilities with 6-second cooldowns.

9: Consecration (9-1), Holy Shield (9-2), Judgement (9-3)
6: Hammer of the Righteous (6-1), Shield of Righteousness (6-2)

If you do it with no hiccups, you will always have 4 abilities on cooldown with one coming up to make it pretty easy. You go 6-1 > 9-1 > 6-2 > 9-2 > 6-1 > 9-3 > 6-2 > 9-1 etc. You can make a pair of simple castsequence macros for two-button tanking if you want, but that'll do ugly things in the long run, so I wouldn't recommend it.

Gear
The basics of paladin gearing are:
540 defense (skill, this is 689 rating)
Dodge and parry (the formula to see if your dodge and parry are on equal DR is [Dodge - 10] / [parry - 10] = 1.88, below this number and you want dodge on gear over parry, above this number and you want parry on gear over dodge. Never gem for parry)
Fill in the gaps with block rating
Pump up your threat stats and stam (Str is the best threat stat by far, with hit/expertise coming close, block value in third and weapon speed factoring in there thanks to the new Seal of Vengeance)

Gems: blue gets +stam, yellow gets +def/+stam, red gets +agi/+stam.
Enchants: Argent Crusade for head, Hodir for shoulders, leatherworkers for pants. Defense to chest/shield/cloak, stam to bracers, your choice for gloves (Armsman, +armor from engineering, and Hit/Expertise all have good arguments), your choice to weapon (Mongoose, +agility, Accuracy, Blade Ward, Blood Draining all have good arguments).
Glyphs: Divine Plea, Seal of Vengeance, and either Judgement for TPS or Righteous Defense so your taunts never miss.

A good beginner's guide to gathering tanking gear for heroics is available here: Eanin's Failsafe WotLK Gear Guide. You can feel free to ignore it if you have some BoE epic, Argent Tournament piece, or heroic ToC 5-man, but it's a very good guide to getting your gear early.

The Hard Parts

Being a tank is all about making sure you keep aggro and everyone stays alive. You have a lot of tools for that second part. Make sure you have the following abilities handy at all times:

A bubble/unbubble macro to break CCs on you (#showtooltip Divine Shield /cancelaura Divine Shield /cast Divine Shield)
Hand of Salvation
Righteous Defense (taunt1, best used on healers who have aggro since it taunts three guys)
Hand of Reckoning (taunt2, usable for damage when it's not targeting you for some reason, like a spellcast or Icehowl stun)
Hand of Protection (your third taunt, for when all else fails)
A Lay on Hands macro that targets it on yourself
Divine Protection

Divine Sacrifice, a potion button, and whatever other cooldowns you have (Stoneform and EMFHS are spectacular tanking cooldowns, while Gift of the Naaru/Lifeblood can save your life occasionally).

[Nyrrin]

Dom's covered just about everything I think. Dom's definitely done more theorycrafting than I have, or at least read up more than I have. A couple of other things that I think are worth mentioning, though:

Most socket bonuses are not worth gemming for, since stam really is the end all, be all stat of choice. Most of the time, you can just gem for stamina and ignore the actual color of the socket. Two exceptions: 1) you will need *a* red gem to activate the austere earthsiege (+32 stamina, +2% armor contribution, which is the meta you should be using). 2) I've been trying to pick up any bonus that gives me at least 9 stamina, and ignoring anything else, on the assumption that (for example) 30 stamina is slightly worse than 24 stamina and 10 agi, but 30 stamina is better than 21 stamina and 10 agi. By the same token, arguments have been made for the PvP enchant for shoulders (30 stam and some resilience) over the Hodir enchant. Your mileage may vary.

The other thing is defense above 540, while useful, is not necessary. Depending on how close you're riding that 540 minimum (which is actually a 535 minimum if you only intend to tank heroics), you may want to enchant agi on your cloak, or health on your chestpiece. Point for point, looking purely at iLVL and item budgets, if you're looking to trim off defense, you should trim from the enchants first, then trim from gems.

Happy to talk more in game, I'm out of general purpose advice I think.