If you are interested in a working sample instead...

You can download a complete N-Tier sample (with Source in C#,Vb and J# along
with their Visual Studio Solution's) of the Northwind Traders database at

http://www.techmatica.com/aspx/download.aspx

(Under the  Sample section click on hyperlink for Northwind Traders Sample)

Hope this helps

Regards

DotNetGenie - An N-Tier Code Generator
http://www.techmatica.com

We started using Rocky's Business Objects framework and are having success -
http://www.lhotka.net/ArticleIndex.aspx?area=CSLA%20.NET

You can find tons of great info here

http://msdn.microsoft.com/architecture/

and also here

http://msdn.microsoft.com/architecture/application/default.aspx