You covered a lot in this chapter. You started with the lowly "Hello, World!" form and worked your way up to building fully functional Win Forms. Along the way, you explored a number (most, actually) of the more common simple GUI controls provided by the .NET Framework class library. You should now be able to build a simple Win Form with a high level of confidence.
In the next chapter, you will continue to look at the GUI interface provided by the .NET Framework class library, but this time you look at some of the more advanced Win Form topics such as views, menus, and dialog boxes.