Test Your .NET 3.5 Apps: Figure 2: Create a Sample Time Sheet App.
This article relies on a small time sheet application to demonstrate the principles of unit testing. Pictured here is a Windows Forms version of the app; the sample code includes a Web-based version of the app, as well. This application has only five entry fields, but still requires nine business rules. A much larger application would obviously have a (significantly) higher number of business rules that you would have to account for.