Learning server programming

I'm looking for information on learning how to write stored procedures
and server-side programming in general. The docs provide a reference,
of course, but that only tells what one can do, not what one should do.
In particular, I'm interested in how server programming fits in with
system architecture at large. I have in mind issues such as O/R-mapping
when the database isn't just a dumb data store, handling of tasks like
authorization in the application or in the db server.

Any recommendations where to start reading?

Michael

--
Michael Schuerig                           The more it stays the same,
mailto:michael@schuerig.de                        The less it changes!
http://www.schuerig.de/michael/      --Spinal Tap, The Majesty of Rock