CS4482: Tools1 - Learn the Unity Editor API
First Tutorial Link: http://unity3d.com/learn/tutorials/modules/intermediate/editor/building-custom-inspector
Second Tutorial Link: http://unity3d.com/learn/tutorials/modules/intermediate/editor/drawdefaultinspector-function
Third Tutorial Link: http://unity3d.com/learn/tutorials/modules/intermediate/editor/adding-buttons-to-inspector
Fourth Tutorial Link: http://unity3d.com/learn/tutorials/modules/intermediate/layers