Last year Chris Craft wrote this excellent "30 days of .NET" articles where he wrote 30 .NET applications in C# each day. I have gone through the initial few and plan to complete the list as and when I find time. He hasn't actually explained the code and the application logic in detailĀ and that would surely be some task if you are doing 30 apps in 30 days (; You couldn't ask for more.
The source code for all the applications is available. So just download'em and dig through. There's no better way to learn than to dive-in and experiment.