Actually, in the Visual COBOL documentation you will find little or no mention of any of the .NET controls as these are not Micro Focus technology but are instead Microsoft technology. I can normally find excellent tutorials on using the controls by doing a Google search or looking in the MSDN docs. There are also hundreds of books covering ASP.NET and other .NET technologies.
Although most of the examples you will find in this manner are for C# or VB, the basic syntax for using the controls are the same in managed COBOL.
It isn't clear what you are looking for here. What do you mean by how do you update?