my DK is now lvl 70, and still, haven't touched a single hotkey on it. I wanna learn how to play a DK too !
http://www.noxxic.com/wow/pve/death-knight/frost/dps-rotation-and-cooldowns
Unholy Death Knight DPS Rotation Cooldowns 5.0.4 Guide - Noxxic: WoW
Blood Death Knight Tanking Rotation Cooldowns 5.0.4 Guide - Noxxic: WoW
DK's are hilariously easy to start, hard to master. to some extent, it's a lot easier to gear and hit the buttons adequately if you have a decent set of addons to monitor procs, as death knight rotations are all about procs. (and resources, but still, just procs)
To an extent, that's all that frost is, 80% of the time is watching for rime/killing machine to proc, and hitting FS/HB. frost, is your whack-a-mole class. there's some other shit going on (that takes time to adequately grasp i.e. runic power and death runes), but that's genuinely the magic of the spec. stand behind the boss, avoid the fire, hit AMS or AMZ when standing in "magic" fire, have a macro for IBF/AMS if you can't move fast enough, hit FS/Ob when you get KM. get loot.
(the hard stuff comes later on, with runic power and survival/utility, and trying to eek out 10% more DPS by swapping the order in which you hit keys to proc things faster/manually.)
frost is easier to start with, and amusingly, does more damage than unholy. if proc watching (waiting for rime/KM to proc) isn't your thing, or you have weak gear, unholy is a far more predictable DPS rotation, and has a decent burst, making it a good spec for raiding, which usually needs a DK to keep things off the tank, or near the tank, or to kill specific things first, etc.
start with the procs before you get into worrying about weaving death runes in, or using some of the more token abilities like pillar of frost, ERW, blood tap, or even army, you won't get the hang of using those until you hit heroic modes, and/or die shamefully a severe number of times. try not to copy people in LFR, that's not how or where you learn to tank or DPS, it's just for loot.
addons or packs, like ElvUI (v4.00) (or inline auras, quartz, xperl, shadowed UF, nuggets, etc. for watching cooldowns) and when it gets updated, power auras, and spellflash will show you 'next in line' spells, and when to use frost strike/obliterate, or death coil (frost/unholy) as they proc, or when you're RP capped and need to use those abilities.
it's more important on say blood tanking, for when you need to keep survival options open or mitigate attacks from the boss, or just spamming death strikes to regain health, or using AMS/AMZ as a proactive measure.
if you want to learn blood tanking, it's really not that hard, there's only 10 (16) rules, some of them repeat.
1. whatever you do, someone will want to kill you. that's usually the healer, but sometimes, the DPS too. very occasionally it's the boss you're fighting. hit your cooldowns, or hit the whisky. see #10 and #10a
2. face the boss away from the group, sometimes you have to move the boss or attack 5 distant mobs instead of 1. drop DnD as you run into/through the group, turn around/face them away from the players, and take baby steps backward while death/heart/runic striking and you can move all of the mobs in a group so they don't hit your back. this gives you time to avoid walking off cliffs, and keep an eye on the DPS. blood boil and DnD share the approximate radius, so you can use BB instead of DnD to pull those distant mobs into melee range where you can use pestilence or icy touch to "tag" them with a disease and hold threat on them. use pest+ BB to maintain diseases on larger groups of 3 to 12 mobs (when you can do this quickly and easily, it looks awesome)
2a. use strangulate if they don't want to move, dark command if strangulate's on CD.
3. always drop DnD. because nobody waits for the tank to pull initial aggro. use heart strike often, or blood boil every minute to keep your threat up on 2+ mobs so the DPS don't pull them.
3a. tanking multiple mobs is harder and takes practise, use tab to swap targets, dark command/grip on mobs that the DPS pull by accident, then icy touch to hold them. get a threat watching addon like omen and a threat based plates addon, like threat plates or ElvUI, it will make tanking 4000x easier when you can see if the DPS are hitting the wrong mob so you can tab over to it, before it turns around and kills the DPS that pulled it.
4. always, always assume DPS will attack the wrong mobs, be ready to switch to a target to death grip them into melee range. icy touch should hold initial threat and then grip/strangulate/command them into melee range.
4a. use raid markers (skull, x, moon, sun, square, triangle) to indicate CC and priority targets, like healers and hope that perhaps the DPS will take over the job themselves if you forget.
5. From the Healer's POV your job is to keep the healers from breaking down and leaving. The DPS are a distant 8th or 12th concern.
6. again, the healer is the most important person, watch their mana, and don't pull until they have full health and mana.
7. its up to you if you wait around for the hunter to summon a pet or be rez'd after falling off a bridge or through the floor, it's really only you and the healer in the group.
7a. "if you pulled it, you can tank it". this goes double for hunters or mages.
8. no matter how retarded the group is, it's always going to be your fault if you die.
9. in heroics, everyone else says they are a "better tank", in LFR, they usually are. it's probably not personal.
9a. that said, everyone in cata heroics usually has 6+ alts now... they just might be. again, it's probably not personal.
10. tanking is a mentality of suffering more than anything else. occasionally you're the leader, or the awesome tank. *very* occasionally.
10a. "diaf fail dps" is not the ideal way to start or end a conversation, no matter how you feel about the group.