Now that you know a little more about buttons and images, you need to understand how a libwiigui project should be set up. One thing that is confusing for people trying to use libwiigui (or at least it was for me) is that there seem to be two different libraries. This is not true. The bare library is only what is in your libwiigui folder. Everything else (menu.cpp, video.h) is not part of the libwiigui library. They simply lay down the recommended way to effectively use the library. You will not need to worry much about any files except for ''menu.cpp'', ''menu.h'', and ''demo.cpp''.
''demo.cpp'' is your main cpp file, where your program starts in. If you want, you can rename this to ''main.cpp'' or something you see fitting. This file will just call a couple functions to initialize things, maybe set a few variables for you, and then calls your MainMenu() function, which takes care of everything else for you (unless you stop the gui for something else).
''menu.h'' is what declares a couple of functions, and "enum's" the variables that will "describe" your menus (not exactly, but close enough for us). So both of those files are simple, just a few function calls, and a few declarations.