Most modules can be found in this thread:
http://www.shrapnelgames.com/cgi-bin...;f=60;t=000151
There's also a new module in the dungeon odyssey patch, the crack of doom.
make sure to download the patch, I think you need to have it for the other modules.
All modding tools come with the game. there should also be some .pdf files that explain what they're for and how they work.
have fun