Welcome to the DK post, even more so than rogues there are MILLIONS of DK’s out there and MANY MANY MANY of them are baddies, DONT BE ONE OF THEM! When I made my DK at the start of WoLTK I wanted him to be a Tank. I set a goal to gear him up as a tank (not an easy feat as any good tank will tell you, you have the most pressure on you out of the other classes, and getting into tanking is a pain in the ass because nobody wants and undergeared tank, also no tanks want you to come as DPS and roll on their gear so its a lose lose situation) Once you get good however your name will spread and I was getting paid upwards of 300G to tank random heroics for people because they knew I could do it quickly and I could do it well. Back to my goal, I wanted to gear him as a tank, get into a guild, make my way up in that guild and become the guilds Main Tank then go toe to toe with the Lich King and defeat him. I accomplished this goal and it was amazing. I managed to become a top official in the guild with permissions only lesser to that of the GM, I also led our Group1 Raid team.
This spec has the best TPS, has improved self heals, and has a raid AP buff.
DnD can be used on single target or multiple target pulls, especially if you have 2pT10 and Glyph for it (combined +40% dmg) If its a multi-target pull I generally use DnD, IT, PS, Pestilance, DS, HS, HS. Using Rune Strike at every opportunity. Being a DK you have to learn rune-management if you see say (adds spawning in 10 seconds) I would try to get 2 Death Strikes off so as to have 4 death runes (wild cards) this way with 4 death, 2 blood I can easily DnD, IT, PS, Pest, BB and have aggro on the group. After the initial disease spreading there is no set rotation, Use Rune Strike and Icy Touch to get aggro when needed, make sure to keep diseases up to keep that dmg and TPS.
Managing your cooldowns is VERY important as a DK. Especially with the ICC Dodge nerf. This leaves you with pretty much just parry to save you. I use Blood Tap (12% reduced dmg 4pT10) and Vampiric Blood (Increases health by 15% and you generate 35% more health from spells / effects) together as one CD usually, and Ice Bound Fortitude by itself, Anti Magic Shell when magic dmg is comming, If I know a boss is going to hit me hard or if healers are having trouble I use Mark of Blood (heals the target of what I cast it on for 4% of its total health every hit for 20secs or 20 hits) And in cases where I need a quick heal I use Rune Tap (uses a blood rune and generally heals me between 15-20k) Deathstrike is not a “cooldown” but it heals for the most out of your damage abilities and also does nice threat so when low on health I spam Death Strike as best I can.
The 2 and 4 piece bonus’ are nice I would try to get those as quick as you could. Stam is important, however I feel gemming pure stam is a bad idea. First thing you should look at is Def Cap. If your not there that is the #1 priority, if your over you can begin to stack stam / mitigation. If its a blue socket, go ahead and put stam. Red slots I use Parry / Stam, and Yellow spots I have Def / Stam (being over def cap is ok to an extent)