Epic Madness

Ok, I'll try and recap all the known starting locations for the Epic Weapons quest lines. I believe that you must be level 80 to begin these quests, although that is not confirmed in every case.

Assassin

Examine Mark of the Emissary, picked up in Nektulos Forest

Berserker

Talk to Kerran ghost in Sinking Sands at
(-1026, -230, -1209). This is close to the Silent City back door. The quest you
get is different depending of if you are Freeport or Qeynos aligned.

Brigand

Loot "a wanted poster" from an Iksar insurgent in Jasath Wastes

Coercer

Quest begins with "an incandescent wand" dropped off of
a mist goblin in Kunzar Jungle. Reports are that you should have a mist goblin charmed to do the killing, which is kind of poetic.

Conjuror

Ice dervish named psychomalleable ice in Temple of the
White Lady (Skyfire Mountains). Right click on this guy to get started.

Defiler

Kill a 80^ mob in the NE corner of Fens of Nathsar named
Guagua, who drops a notrade item "An Old Medicine Bag". Take this to
Crowhood the Olden on the beach nearby.

Dirge

Any mob in Sebilis will drop a "Quill", which is the starter.

Fury

Walk by "a mutilated deer" in Darklight Woods
( 191.37, -43.61, 167.14 )

Guardian

Jimbo at Windstalker Village in Antonica. You must
have the Bone-Bladed Claymore in your possession. The Screaming Mace is also
needed at some point. Which has led to groups of 6 guardians camping Agony,
the starter. I just finished The Screaming Mace three days ago, so I'm having
some schadenfreude over this one.

Illusionist

Kill "a rillissian slaver" near the slave pens in
Fens of Nathsar for "a pens cell door key". Use the key to open a door in
the top section of the Western Pens. Follow the hobbit.

Inquisitor

Get the drop "Defaced Leaflet" off named fishmen in
Chelsith. Only seen in Exquisite chests so far. Yikes! Developers confirm it's not
supposed to be this rare, expect a fix soon.

Monk

There is an NPC on the beach in Fens of Nathsar. Monks must have both The Teachings of Master Wu and The Journal of Wu in their inventory

Mystic

Starts in Sebilis. Talk to Terrus (-73,-131,122). You must speak Sathirian (Strange Black Tome quest). Terris will give you the "Torn Page of Terrus Notes". Then head to Kunzar Jungle, near the City of Mist and kill a timeworn spirit. You will get a chest which contains a "rune covered stone". Examine the stone to start the quest.

Necromancer

Talk to Tohsa B'hondus at the Academy of Arcane
Sciences in Freeport. She will mention her teacher. Then talk to Qurst in
the Steelbone family crypt in the Graveyard. Then talk to the erudite he
mentions, Dartain, in Neriak (-708, 32, 233).

Paladin

Jailhouse in WFP. That's right, West Freeport, in
the Militia house, downstairs.
You can handle those Epics, can't you, they're only level 70!

Ranger

"A Blackened Arrow" which drops from trakaraptors
in Kunzar Jungle.

Shadowknight

At the bottom of the Academy of Arcane Sciences in
North Freeport. You must kill two mobs for a chest drop "hiring contract".
Not in Qeynos, like the paladins. Symmetry is for suckers.

Swashbuckler

NPC in Timorous Deep, north of the docks area, on
a Pirate Ship. Open a cage on the deck and pick up Rrarwck. Summon him to start
quest.

Templar

This epic begins with an NPC named Aliona Maybelle, who is in Teren's Grasp in a tent near the mailbox. She is sick and wants some healing. Without giving you a quest, she will ask you to gather Stonewood Jasper Blooms, which can be found to the south of Karnor's Castle. Return to her with them, and she will give you a recipe to scribe and make with them and some other gathered materials. Finally, when you have made the poultice that the recipe describes, you will get the first quest in the series.

Troubador

Talk to someone in Thundering Steppes at (53, 0, 1390).
Go to East Freeport and talk to "lyrist"s. Two of them, they talk a lot. But then,
so do you. One is on the broker island, the other on the stage. Finally, go to
Qeynos Harbor and talk to the two lyrists there. There is a book both
in the Academy of Arcane Sciences (Freeport) and in the
Tower of Three(Concordium, Qeynos) with notes floating over it. Click it.

Warden

Starter is "a shifting elemental shard" dropped by
"a shifting ethereal elemental" (80^^^) in Kunzar Jungle somewhere in the raptor
valley. It teleports around quickly, so be prepared to smack it as soon
as it shows up.

Warlock

Click a dagger on
the fireplace in the Seafarer's Roost Inn, East Freeport.

Wizard

Kill trash mobs in Chelsith to loot "A Dilapidated Journal"
from a small chest. Read the journal.

It looks like these quests use all the zones, and all the items in all the game. I'm not sure what you do if you've destroyed, any of these items, but the Shady Swashbuckler on the Nektulos Forest docks is a good place to start.

Update: I've added in the starters for Mystic and Templar as they have become available. So the list is complete now. I'll make a few observations in another post later.