In this hour, you learned the basics for debugging applications. You learned how adding useful and plentiful comments to your procedures makes debugging easier. However, no matter how good your comments are, you'll still have bugs.
You learned about the two basic types of errors: build errors and runtime errors (exceptions). Build errors are easier to troubleshoot because the compiler tells you exactly what line contains a build error and generally provides useful information about how to correct it. Exceptions, on the other hand, can crash your application if not handled properly. You learned how to track down exceptions using break points and the Immediate window, and you learned how to send text to the Output window at runtime. Finally, you learned to how to make your applications more robust by creating structured error handlers using the try structure.
No book can teach you everything you need to know to write bug-free code. However, this hour taught you the basic skills you need to track down and eliminate many types of errors in your programs. As your skills as a programmer improve, so will your debugging abilities.