I am teaching a computer science course to senior level high school students. Part of my class includes introductions to different OS's. Any suggestions for good books to recommend for those students who want references? The list should include both sources for desktops and servers. Danke.

Sobell, Mark G. - A Practical Guide (to Linux Commands, Editors and Shell Programming) - Prentice-Hall, 2005
Kalle, M. & M. Welsh - Running Linux : A Distribution Neutral Guide for Servers and Desktops - O'Reilly,2005
Bovet, P. - Understanding the Linux Kernel - O'Reilly, 2005 (a guided tour of the kernel code)
Siever, E. et alii - Linux in a Nutshell: A Desktop Quick Reference - O'Reilly, 2005 (this is more of a reference than a manual - excellent but not recommended as a starting point)
Matthew, N. & R. Stones - Beginning Linux Programming - Wrox, Wiley, 2004
Pritchard, S. & alii - LPI Linux Certification in a Nutshell - O'Reilly, 2006

Also check the LQ Book Reviews