Note: This is all from my own experience, I haven't copied any of this from anywhere, I typed it all out myself. Also, don't take this all for gospel, as I said it's my own experience and how I play, so
that doesnt mean it'll be the best for you, as everyone has a different play style.
Areas I will cover:
Spec
Rotations
Gear
Spec.
I personally use this spec - The World of Warcraft Armory
This provides a good amount of self healing, through Bloodworms, Runetap, Imp Blood Presence and having your ghoul up all the time for Death Pact. This spec is good for AoE tanking, and also if your doing a heroic
or something and your healer is borderline then you are able to heal yourself more than any other spec.
Glyphs - Major - Glyph of Disease - This allows me to refresh my diseases on all targets with only one blood rune, as opposed to one of all three runes.
Glyph of the Ghoul - I really only have this glyph so that my ghoul doesn't die during AoE, so that I ALWAYS have death pact avail.
Glyph of Icebound Fortitude - Balances out gear, makes this spell alot more useful for lesser geared tanks.
Minor - Glyph of Horn of Winter - So that I don't have to apply it as often.
Glyph of Raise Dead - Because I can't be assed buying reagents all the time.
Rotations.
Always tank in Frost Pres.
When I pull, I always throw Death and Decay down where I will be tanking the mobs, and then pull. If the group has a caster in it, I would Death Grip the caster, and then Icy Touch and Plague Strike. If there is no
caster or ranged, I will start out with Icy Touch. Once I have my two diseases up, I use pestilence to spread them to all mobs, and then when my Blood rune comes up, Blood Boil. By now I usually have enough
Runic Power to use Unholy Blight, so I do that. The fight carries on pretty much like that, casting Pestilence when my diseases are almost running out, and Blood Boilling on CD. If my HP drops below ~30%
I'll throw Icebound Fortitude up, and pop my trinkets. This gives the healer a little more time to get a big heal off. Also if I drop below around 60% I'll use Rune Tap, just to keep me topped up. I tend to save
Death Pact for if I get knocked back, or my healer gets knocked back and isn't in range or LoS to heal me, I'll only pop it if I'm below 20% HP, and then I'll Healthstone / Pot / Rune Tap, usually this will keep
me alive until heals gets back.
Gear.
Going into Norm Naxx you want to have atleast 540 defence rating, this is an absolute must. You want to have around 40-45% total avoidance (parry + dodge) and about 25-27k hp unbuffed.
All this, and better can be achieved through crafted gear and heroic / EoH gear. I'm not going to give you a gear list and what enchants to have etc, its really not hard to get this, if you really want a gear list Google it.
Try and keep your avoidances (Dodge and parry) somewhat equal, theres no point in having all dodge and no parry, or vice versa. However, take dodge over parry, as parry does reset your swing timer
and can mess up your rotations depending on what spec you use.
I know this is rather vague, and will soon be completely redundant, but I wanted to contribute something about DK Tanking, as it will soon be very different.
Enjoy
Damare0.