Found some time again to work on linux-training.be. I reviewed the Linux Fundamentals book(pdf) (biggest changes are in chapter 9 permissions).
It is still not complete, but good enough at the moment. Imho it is missing chapters (or appendixes) about regular expressions, sed and awk (and maybe some more info about other commands like pr, expand, nl, fmt, join, ...).
I am also a bit annoyed because the processes chapter is in Fundamentals, I consider it a System Administration topic...but students almost always demand (and enjoy!) this chapter.
Many thanks to Wouter and Geert for the feedback, to Serge for hosting the svn and rss feed and to Inge for the cover design.
Time to tackle the System Administration book(pdf)...it needs a lot of work!