Red Hat Enterprise Linux Introduction to System Adminitration; Red Hat, Inc — This companion manual provides an overview of concepts and techniques of system administration. The chapter titled Managing User Accounts and Resource Access has great information pertaining to user and group account management.
System Administrators Guide; Red Hat, Inc — This companion manual contains more information on managing users and groups as well as advanced permission configuration using ACLs. Refer to the chapters titled User and Group Configuration and Access Control Lists for details.
Security Guide; Red Hat, Inc — This companion manual provides security-related aspects of user accounts, namely choosing strong passwords.