Documentation

Examware
Unix tutorials, exercises and resources. Features on-line tests and training materials.
http://examware.com/tutor5.html

First Edition Unix Manual
The original Unix users manual.
http://cm.bell-labs.com/cm/cs/who/dmr/1stEdman.html

Online Single Unix Specification
Ordering page for the Open Group's Single Unix Specification.
http://www.unix.org/online.html

pyttymon
A simple daemon that monitors and limits usage of ttys. It is implemented in Python. A simple config file can specify monthly, daily, session, and idle limits based on tty, user, group, and ttys in use.
http://freshmeat.net/projects/pyttymon/

Understanding Unix Concepts
Conceptual discussion of Unix and Unix-like operating systems.
http://www.uwsg.iu.edu/usail/index/concepts.html

Unix and Linux Commands
Basic as well as more obscure commands for Unix/Linux operating systems.
http://www.laynetworks.com/linux.htm

Unix Filesystem
Description of how the filesystem works internally.
http://www.angelfire.com/myband/binusoman/Unix.html

Unix for Advanced Users
Description of startup/shutdown, process management and memory management.
http://www.uwsg.iu.edu/UAU/uau.html

Unix Manuals
Brief Unix tutorial, online man pages and reference materials for the Unix operating system and common Unix utilities.
http://www.unix-manuals.com

Unix Seventh Edition Manual
Source material from Bell Labs.
http://www.cs.bell-labs.com/7thEdMan/

Unix Signals and Process Groups
Short survey of Unix signal handling and process groups, conceptually and with interface descriptions. Compares System V Release 3, System V Release 4, BSD, and POSIX variants.
http://www.frostbytes.com/~jimf/papers/signals/signals.html