I know it is a lot of text, and not much looking around, as we all love to look at pictures more than reading! However it is really important to have read all this, understanding his abilities and what effect it can have on the raid is one of the key factors of this fight. It all comes down to survivability, and for this you need knowledge on what can happen and what should not happen.

Archimonde

HP - 4,600,000
Melee Strength - 7,000 on plate. He can not land a Crushing Blow.

This would suggest a Druid tank is favored, but due to Fear it is not, a Warrior Tank can stance dance (which is needed) a Bear Tank can't.

Doomfire
Roughly every 30 seconds, Archimonde will call down a huge trail of fire. Each section of the trail of fire lasts about 27 seconds before it disappears. It 2-3 yards wide, and spawns in one spot and then gets longer and longer as its "head" moves around.

If you step in the fire, you take 2400 damage every second, and you get a non-dispellable DoT called Doomfire that does 2250 fire damage to you every 3 seconds, decreasing by 150 damage each tick until it reached 0, for a total of 20400 damage over 45 seconds.

Soul Charge
Whenever a person dies (pet deaths don't trigger it), his "soul" flies to Archimonde. When it reaches Archimonde, he gains a Shadow Orb. Once he gains a Soul Charge, he will usually use it on the raid after about 5-10 seconds (though it is not fixed, and could be instant or after a long pause).

There are 3 different charges depending on which class died. They are as follows:

• Purple(Red) Soul Charge (Priest, Paladin, Warlock)
  Deals 4500 fire damage to everyone in a 200 yard radius, as well as silencing them for 4 seconds.
• Orange(Yellow) Soul Charge (Warrior, Rogue, Mage)
  Increases all damage taken by everyone in the raid by 50% and deals 4500 physical damage (decreased by armour) to everyone in a 200 yard radius.
• Green Soul Charge (Druid, Shaman, Hunter)
  Deals 4500 nature damage over 8 seconds (1125 every 2 seconds), in addition to draining 2250 mana from everyone in a 200 yard radius.

There is no limit to the number of Soul Charges Archimonde can have, so it is very easy for one death to trigger a Soul Charge which kills a few more players, resulting in a cascade of deaths and Soul Charges.

Grip of the Legion
Used randomly, and very often (if not constantly), it places a curse on a random target, dealing 2500 shadow damage every 3 seconds for 5 minutes (250,000 total). He won't cast this on somebody who has just been Air Bursted.

Air Burst
Inflicts 1500 nature damage to everyone in 13 yards around the targeted player (including the player themselves), tossing them high up and back into the air (over 100 yards away from Archimonde), after which they will simply fall down. Will not be used on the player at the top of Archimonde's aggro list.

Fear
Cast regularly at 40 second intervals. Fears everybody in a 200 yard radius for about 6-8 seconds.

Finger of Death
The description of this ability, straight from the WoW spell descriptions, states, "Strikes an enemy with the finger of death, inflicting 20000 shadow damage upon them, their children, and their children's children."

He uses it when there's nobody in his melee range, but never during the pull. Basically it's a wipe ability he uses just to kill you off faster after your tank dies.

How to deal with each ability

Doomfire
Archimonde often has two Doomfires active at once. They sometimes follow a player, then suddenly run in a completely random direction, then follow a player again. Thus, the best thing you can do is watch out and run if it goes for you. What is important to remember is what Anaro has made clear quite nicely right here (thanks dude!): http://vigilantes.zind.net/forum/archimonde-brainstorming

REMINDER: It is better to run away from Archimonde while being chased then side-stepping, as side-stepping makes it more unpredictable!

This debuff can be removed with immunities like Cloak of Shadows, Iceblock and Divine Shield, other then that it just needs to be healed through. However people actually should not get hit by Doomfire whatsoever!

Grip of the Legion
Eventhough the damage is significant it is quite easy to deal with this ability, it is however important that Mages and Druids are on their toes with decursing here! Throughout the raid we want a maximised spread of the decursers so we can reach each and every person in the raid. So decursers: decurse > all!

Soulcharge
One Soulcharge is one to many, so any death is bad! Try and stay alive, that's what this fight is all about, survival.

• Purple(Red) Soul Charge (Priest, Paladin, Warlock)
  4,500 damage done and a 4s Silence usually means a dead MT, which results in a certain wipe. Of course you can try to recover from this, basically by healing the raid back up after the Silence is gone.
• Orange(Yellow) Soul Charge (Warrior, Rogue, Mage)
  4,500 damage done and 50% extra damage on everyone in the raid, the initial blow is not that bad, we can probably heal ourselves through. 50% extra damage done is painful and will most likely result in a wipe.
• Green Soul Charge (Druid, Shaman, Hunter)
  4,500 damage over 8 seconds, this can and should be healed through. The aditional mana drain of 2250 mana is not that shocking, however if you're already low on mana (coming to the end of the fight) this can be a killer. This is probably the least painful Soulcharge, however we prefer none at all!

Air Burst
Air Burst has a 6 second cooldown, meaning it can be used every 6 seconds, but it can also be used after 20 seconds or even a minute. It can only be cast on a person in 60 yards of Archimonde so it cannot be cast twice on the same group of Air Bursted players.
An Air-Burst tank does not lose aggro, but your tank should not be hit by Air Burst if everyone positions correctly. This is really important as the tank will most likely get out of range of the healers and die in the air, resulting in a wipe.

In order not to die from this ability, you need to use the Tears of the Goddess, which you can get from Tyrande Whisperwind at the entrance to the night elf camp. The Tears of the Goddess is an item in your inventory that when used (by clicking on it), slows your fall (like Slow Fall or Levitate) for 2 seconds, after which you resume your normal fall speed. It has a 10 second cooldown.
In order not to die from the fall damage, you must use it when you're almost at the ground. If you lag, use it even earlier; it's better to use it early and take 2000-3000 fall damage than not be able to use it at all and die.

Tears of the Goddess [1]
Use: Briefly slows falling speed.

Fear
There is a very high chance your MT will die in the time you are feared, so you must pick pairs of about 2 healers a time who will trinket/ability out of the Fear and heal the MT at all cost! As Fearward is kind of wasted on the MT, as he/she will be stance dancing anyway, Fearward can be used on healers whenever it is up.

When you are running towards the Doomfire while feared, you must get out of the Fear or the Doomfire has a very high chance of killing you while feared. There is no room for healing you back up from the Doomfire ability, specially not while learning the encounter.

Will of the Forsaken, PvP Trinkets, Divine Shield, Ice Block, Cloak of Shadows (while it's cast), Fear Ward, Tremor Totem, all can be used to avoid this ability.

Finger of Death
As said before it is a wipe-ability so there's nothing else to do here and die

10k HP is needed for just about every encounter now

Possible tips that will be implemented into the guide :

1) <3 shammys tremor totems for fear, having 3 may well boost raid learning speed
2) Stacking shamans and resto druids makes it 10x easier. Raid wide tremor. Decurse/Heal coverage for everyone + Hots for your MT while feared.
3) Hugging (to some extant) around a decurser so can be done during airburst
4) The goal of any raid leader should be to get your raid to understand how bad Doomfire is.
5) The goal of all non-melee dps classes is to just not be a liability.
6) Purification Potions save lives

stay tuned more to come

Havent had much time on working on this, but I also want to wait and see how it is going this week to see if there are major changes coming up (spreading, 3-4 point strategy etcetera).