In this category ‘Distributed app’ I will post the articles which I reckon should be read those who are  interested in the enterprise architecture and are working with the n-tier systems.
 
Interestingly, that all general aspects of the n-tier apps were completely described about 8 years ago by Mary Kirtland in her book ‘Designing Component Based Application’ that was published in 1997. Since then nothing was changed to be new in the basis of the enterprise architecture. All ideas are still the same, only platform changed a bit.
I would like to add that only one thing became new – SOA, 8 years ago we hardly have an idea how it could be realized and work.

First article I recommend to start is "Designing Data Tier Components and Passing Data Through Tiers". It describes DAL and BAL components with examples and several scenarios with pros and cons. Moreover it provides some code snippets of how to create components, apply XSD, and etc.

Another interesting article for newbies is "Building an N-Tier Application in .NET" and this one "DataSets vs. Collections"