Hi Dean,
The best way to learn about n-tier & SOA architectures is through research
and experimentation.
Adhering to standards & best practices will cost you more time initially but
will save you effort in the long run.
To learn about Service Oriented Architectures the number one resource I can
recommend is the WEFLY247 project, microsoft developed this Example enterpise
application for poeple who are new to Visual Studio 2005, if you can come to
grasp the concepts expressed in this project you will be well on your way to
developing professional enterprise application architectures.
http://wefly.learn247.net/
Microsoft also recently released an update of the "Enterprise library" this
is a solution filled with various projects that handle common enterprise
tasks like "Event logging, cahcing etc.
http://go.microsoft.com/fwlink/?linkid=52387&clcid=0x409
Your mail goal, it seems is to learn more about application architectures
http://msdn.microsoft.com/architecture/
And last but not least, a search results list on SOA:
http://www.google.co.za/search?hl=en&q=filetype:pdf++SOA&meta=