The Mines of Glooming Deep
Continue east to where it says "Dig Site One" on your map. Here you need to kill 5 Gloomingdeep Grunts, 10 Gloomingdeep Warriors, 5 Gloomingdeep Slave Wardens and 1 Gloomingdeep Spiritweaver. The Warriors and Grunts can be found at Dig Site One, as for the Spiritweaver's and Slave Wardens, you can find them at Dig Site Two.
Once you hit level 6 return to the Guards and hail Guard Maddoc. Accept his task then continue killing the Kobolds.
Items of Interest:
After you finish killing these kobolds head a tad west of Dig Site Two you'll find Revolt Scout Kaiachi and Zajeer. Hail both of them and accept their tasks. After you have both tasks head back to Guard Hobart and hail him to complete your quest. If your inventory is getting full return to town and sell. If not turn around and head east to where it says "Fort Gloomingdeep" on your map.
Over near Fort Gloomingdeep you need to kill 4 Glooming Deep Captains, and inside the fort, if you can Overlord Gnikan. If you have a merc you will breeze right through him. If you don't have a merc he may put up a fight, but you can still take him. If you can't kill him now just come back later.
After you've killed 4 captains, your task will automatically complete. Before you leave Fort Gloomingdeep you have one more task to do. You need to destroy a crate near the Fort. If you're leaving the fort, to the right of the bridge will be the crate. Run over to the Crate and trade it to the Makeshift Lantern Bomb, similar to how you handed Absor your weapon earlier. After you hand the crate the bomb you will get credit for completing your quest.
If you killed Overlord Gnikan then return to Guard Hobart and hail him to complete your task. After you've done that head back to Dig Site Two and kill the Goblin Slaves here for your "Goblin Treachery" Task.
You won't be able to kill all 10 right now, don't worry we'll come back later to kill some more! After you've killed the 4 or 5 goblins that are here head back to Revolt Scouts Zajeer and Kaikachi. Hail Zajeer to complete your task then head north to the Jail Cell area.
Open Jail Cells as you go and kill the remaining Goblin Slaves that you need. Also keep an eye out for The Gloomingdeep Locksmith.
When you find the Locksmith kill him and loot his key to complete a part of your "Busted Locks" Task. After you've killed him and all 10 Goblin Slaves return to the Revolt Scouts. Hand Revolt Scout Kaikachi they key to complete your task.
Now for one of the last parts of the mine. Return to Dig Site One and go down into the pit. You can find Rookfynn through the western hole in the pit. The picture below will give you a more detailed look of where the entrance to his "lair" is.
After you kill Rookfynn return to Kaikachi and hail him to complete your task. Now to finish off a task we've been holding on to for far too long. Head to the most southern portion of the mine, where the spiders are and kill Queen Gloomfang.
After you've killed her return to Guard Hobart and hail him to complete your quest. If you have a merc, continue reading. If not the next task will be too hard for you.
Hail both guards and accept the quest "Pit Fiend". Head back into the pit, this time on the eastern section. Down through the eastern hallway you'll find Krenshin. Kill him to complete your task.
After he is dead return to Arias and hail him. Type "/say Ready to Leave" to be taken to the Plane of Knowledge.