This chapter got you started. It showed you how to create the beginnings of the Phone Book program using the Hello program from Chapter 3 as a template. And it showed you how to use a C++ object to simplify the interface between Phone Book's Windows code and the data model code from Chapter 2.
With the data model firmly encapsulated, you can continue the tutorial in the next chapter by developing the first parts of the user interface: the dialog boxes by which the program interacts with the user.