I have been looking all over the internet for how to find the assassins guild and if they are in the game, I know that they are but could never find them, and every site I went to that talked about them had no answer on where they are. But I had finally found them and feel i should make a post so that others can find out where they are and what to do. *WARNING* POSSIBLE SPOILERS??? (Not to main story line) you will need to go to the town of Riften and once inside you will meet a guy who eventually talks about a kid trying to contact the DB, he says that he is in the town of Windhelm what you need to do is go there and find him, he will give you a quest to go kill someone, once you do that and go back to the kid. after you are done talking to the kid and he has nothing left for you to do, go find a place to sleep and well... wait to be surprised =) I hope this helps some people because I wish I found a forum like this when I was looking.