Compiled by Michael Hipp from contributions as noted below.
If there's a book that just has to be added to the list, let us know.
All of the O'Reilly books, especially:
"Running Linux", Welsh, Dalheimer, and Kaufman, ISBN: 156592469X
"Linux in a Nutshell", Siever, ISBN: 1565925858
"Using Caldera Open Linux", Smart, et al, QUE Pub., ISBN:
"Practical KDE", Powell, QUE Pub, ISBN: 078972216X
The linux documentation project: http://www.linuxdocs.org
Step By Step Site at http://linux-sxs.org "Don't Do Linux Without It"
"OpenLinux User's Guide" - Caldera Systems
"The Cathedral and the Bazaar" - Eric S. Raymond
"Linux Unleashed" - Bill Ball, Sams, ISBN: 0672316889
Seems pretty comprehensive.
"A Practical Guide to Linux" by Mark G.Sobell,
Addison-Wesley Pub Co, ISBN: 0201895498
"Caldera Unleashed" - David Skoll, Sams; ISBN:
It's a great book. Granted, it's partial to COL 2.3, but only a few things changed from COL 2.3 to eD 2.4. The bulk of the stuff stayed the same.