OPENXTRA is a UK VAR that offers a variety of network management and server room monitoring tools and information. They publish a set of related newsletters, including one on Network Management, although there don't appear to have been any issues published in the last few months (since December 2004).

I haven't read all the articles on their web site yet, but the ones I've looked at so far all seem fairly introductory and high-level; for example, An Introduction to Network Configuration Management is a good very high-level overview of what network configuration management is and why it's useful, but it's fairly short on details. Regardless, I'm glad to see them making these articles available.