NETS1028
System Configuration related links
Ubuntu Security Features
Supplier Security Recommendations for Ubuntu
CentOS SELinux documentation
BookofZeus Ubuntu Hardening Tips
Techrepublic article on securing Ubuntu
OS Protection in CentOS
Basic Ubuntu Security Guide
Ubuntu Forums Blog Post with good tips
Unattended-upgrades Docs
Ubuntu Server Guide Configuration For APT
ACPID lookup on CVE
Ubuntu dpkg doc
Securing Debian Manual
Ubuntu User Account Management
Ecryptfs Info
Hardening the kernel with sysctl
Lynis
Lynis installation instructions for Debian/Ubuntu