Security and Hardening Linux – A paper that is a step by step guide to securing a Linux system for home or production use.
You can download it from the following link: https://packetstormsecurity.com/files/download/61563/Securing_and_Hardening_Linux_v1.0.pdf
Source: https://packetstormsecurity.com/files/61563/Securing_and_Hardening_Linux_v1.0.pdf.html