Apple has put up a nice bit of documentation on their developer site on some the more advanced topics that systems administrator may be interested in.
Topics covered include Kerberizing the Mac OS X VPN Server, Creating Mail Account Bundles, Setting Up a Network Library, Setting Up Key-Based SSH Login and Incorporating User Images in Open Directory.
All of this material is available for reading directly on their site, or you can download the PDF for on the road/plane reading material.
Andrina Kelly is responsible for anything and everything touched by, or connected to, a Mac at Bell Media, Canada's premiere multimedia company. You may recognize her name from the end credits of Canada's evening news broadcast. She has previously spoken at MacSysAdmin, JAMF National Users Conference, Apple's WWDC, Macworld IT conferences, Mac Networkers Retreat, and Canada MacExpo.