Try looking at r4am0n\'s and CardBoardBoxProcessor\'s MechJeb Autopilot. They have a GUI which you can see in their source code, you learn a lot by reading the code. Then we have Unity\'s own documentation: http://unity3d.com/support/documentation/ScriptReference/30_search.html?q=gui And some basic tutorial: http://unity3d.com/support/documentation/Components/GUI%20Scripting%20Guide.html How you apply it to KSP you\'ll have to figure out yourself, or by help from other people\'s source codes.