These are the posts I know about the basic info:
Item Rules: http://www.thebuddyforum.com/demonbuddy-forum/demonbuddy-guides/54086-item-rules-quickstart-guide.html
Profiles: http://www.thebuddyforum.com/demonbuddy-forum/demonbuddy-profiles/54605-all-available-profile-tags.html
Plugins: http://www.thebuddyforum.com/demonbuddy-forum/developers/62941-request-how-initialize-plugin-project.html#post646879
Also you can check Demonbuddy functions by importing Demonbuddy.exe to a C# project in Visual Studio or Express. Then you can see the closest thing to an API in the Object Browser.
There isn't exactly much in the way of documentation, but if you have Visual Studio, you can include DB as a reference and see all the stuff you can do from there






