Arcane University:NPC Packages

AI-Packages (or NPC-Packages) control the behaviour of the actors in Skyrim. They specify where an NPCs works/eats/sleeps, how he behaves in combat or when he discovers a dead body.

See the known issues section for common issues at the bottom when working with NPC-Packages.

Getting Started
To get an introduction, make sure to read: Bethesda Tutorial Packages(Creation Kit Wiki)

Debugging Packages
Debugging AI-Packages is a cumbersome task to do, but there are tools that can help you with it.
 * More Informative Console
 * Package Debug Helper

Once per day flag
the "Once Per Day" flag on a package only works if the package has neither start time nor duration, so it often appears as though it doesn't work at all. - jadkai