You begin the Werewolf quest in the Chanterless Church. If you look at the map, the key is pretty self explanatory, but I'll still go through each marked location just for the sake of continuity. You will notice that Location C is the switch that opens the bars which keep you from reaching the back part of the Church. The code you have to enter for the switch was pretty easy to guess actually. In fact, that's how I got the code the first time I played the game, I guessed:) The code for the door, 666, is written on a piece of paper in the red chest at Location F.
Location A: This treasure chest holds an Iron Sword.
Location B: This crate holds 2 Iron Swords.
Location C: This is the switch that unlocks the "door" barring
your way to the rest of the church. The code is 666.
Location D: This treasure chest is a trap, so be ready to fight a Jaws O'
Treasure.
Location E: This skeleton is not as dead as he at first appears, but
beating him will net you an Antic Sword.
Location F: The code for the door lock is written on a piece of paper in
this treasure chest.
Location G: This crate hides 230 gp.
Location H: Hidden in this crate is 510 gp.
Once you have everything in the Church, go through the door near Location H, and you'll enter the Church basement.