In this tutorial, creation of a basic Windows control library is explained using a "Hello World Control" example. The tutorial also shows how to use this control in VB .NET 

User controls provide a means by which custom graphical interfaces can be created and reused. A user control is essentially a component with a visual representation. As such, it might consist of one or more Windows Forms controls, components or blocks of code that can extend functionality by validating user input, modifying display properties or performing other tasks required by the author. User controls can be placed on Windows Forms in the same manner as other controls.

Components provide reusable code in the form of objects. An application that uses a component's code, by creating objects and calling their properties and methods, is referred to as a client. A client may or may not be in the same assembly as a component it uses.

Please go through MSDN for more information about .NET Components.  Click on the appropriate  link below to see the video and the source tutorials.

Creating .NET Components in VC#