I've finished my PhD thesis some time ago, and as the system described in it is heavily based on NetBSD, I feel it's relevant for mentioning here. The full title is System Administration Training in the Virtual Unix Lab -- An e-learning system with diagnosis via a domain specific language as base for an architecture for tutorial assistance and user adaption''. The book was published in Jan 2009 by Shaker, Germany as ISBN 978-3-8322-7874-8, and it is also available for online purchase and if you look around a bit on my VUlab page, you will find a permitted local copy for downloading as well.