Join or Destroy the Dark Brotherhood in Skyrim
How it all Begins
This is how you begin joining the Dark Brotherhood or destroying it. Travel to Whiterun and enter Aventus Aretino's house at nighttime. Once you enter you will find that he is atempting to summon an Assassin from the Dark Brotherhood. He will assume you are from the Dark Brotherhood and offer you the contract.
If you accept and complete the contract you will have stolen the hit from the Dark Brotherhood. Do it and in some time you will receive a message from the Dark Brotherhood saying "We know". Go sleep at an inn and you will be kidnapped by the Dark Brotherhood.
Making the Choice
After going to sleep in an inn you will wake up in a locked log cabin. Here is you will meet you first member of the Dark Brotherhood, Astrid. Astrid will tell you that one of the three other bound and hooded people in the room have a contract on their head and you must find out who and kill them.
If you wish you join the Dark Brotherhood pick anyone of the three hooded people and kill them. Astrid doesn't care who you kill he just wants to see if you are willing to kill for money.
If you want to destroy the Dark Brotherhood kill Astrid. You will fail your current quest and get a new quest for destroying the Dark Brotherhood.
Advantages of Destroying the Dark Brotherhood
You get to play the quest for destroying the Dark Brotherhood. This is something you probably don't want to do as the only loot you get for a reward is what you can scavenge from the Dark Brotherhood sanctuary and 3000 gold. If you choose this option you are going to miss out on some of the funnest quests in the game. You are also going miss out on a lot of XP and great loot. Some of the best weapons are ones you are going to get from the Dark Brotherhood quests in Skyrim.
Advantages of Joining the Dark Brotherhood
You get to play through the 14 main quests. You also have access you 13 side quests to complete. This is a very big advantage of joining the Dark Brotherhood.
You also get some very powerful weapons through the quests as well as much great loot and XP otherwise.