Recommended Reference

Apple Support Feed [RSS]
This essential feed lists each article as it's added to Apple's public Knowledge Base, keeping readers up to date on official hardware, software, and operating system issues. 

AFP 548 [HTML]
Named after the network port number for the Apple Filing Protocol, this site is a great look at how some skilled administrators manage complex Macintosh systems.

MacEnterprise [HTML]
It isn't pretty, and can slanted towards academic environments, but this hardcore collection of tips, tricks, and scripts (and its accompanying mailing list) is quite possibly the best OS X resource online for serious Macintosh management.

MacFixIt [HTML]
A fanatastic collection of recently reported Mac issues. It may not always have the answer, but it can often inspire it. New material is free for two days, then becomes subscription-only.

MacWindows [HTML]
A very readable (if occasionally advertorial) collection of news, tips, reviews, and user reports on Windows and Macintosh integration and virtualization.

XSanity [HTML]
This small, dense site is by far the best beginner's resource for hands-on Xsan tip and tricks, as well as general wisdom for Apple's shared storage solution.

Mac OS X Server Command Line Administration Manual [PDF - 2.1MB]
The absolute bible for Mac OS X Server management. An invaluable reference for troubleshooting and management.