I have heard a lot of people talk about Firkragg and how to kill him; I'm just wondering how to get to him! I'm in Chap. 3 and have just been finishing as many side quests as possible before I do the 3rd quest for the shadow thieves and finish the chapter. Or do most people not go to Firkragg until much later? Do I have to talk to someone to get the hills marked on my map?

you have to talk to err.. who wasthatagain?... oh yeah... the person somewhere in the copper cornet. he is near the bar tender ... forgot his name ... i think he trying to get you for a quest... anyway ... spoiler... you will find firkragg when you go to windspear hills....

a little more spoiler if you want
-when you get there... you will fight a bunch of monsters, once they are dead you will see that they are paladins you just killed. (they were illusioned)
-to bring back your honor and not being hunted down by thier paladin sect, as well as rescue the daughter of the guide (you will know once you get there)
-his lair is in eastern part of the map and you enter somekind of temple...
-be wary because you will meet there is a greater werewolf (which regenerates really really fast, like 10hp per sec) as well as an adamite golem, the strongest golem in the game)
-you will also meet tazok and he has a key which you can use to open the door in the sewers in the temple district. (the mindflayers area, really hard, but you will get one of the most powerful items in the game once you get all the other 3 things needed to complete it.