Decal System
We recommend you to have a look at the video tutorials and example scenes, if you are using the Decal System for the first time. The demos are bundled in the "Plugins/Decal System/Demos/DecalSystemDemos.unitypackage".
You find more documentation in the "Plugins/Decal System/Documentation" folder. Keep in mind that the Decal System's inspector GUI already contains a lot of explanations.

Videos
Some Decal System videos can be found on Youtube
http://www.youtube.com/playlist?list=PLBD9CA3140ECF817A

Support
If you have any question, suggestion, feedback, criticism or bug report about the Decal System, feel free to post them in this Unity forum thread
http://forum.unity3d.com/threads/141792-Decal-System

If you can not post in the forums for any reason, you may contact me directly
andy@edelweissinteractive.com

License
The Decal System is released under the standard Asset Store license. Only the "Decal System Demos" folder contains assets for which Edelweiss Interactive does not have the copyright. Those files are from Unity's Bootcamp demo.