I am not sophisticated enough to critically assess these documents, but here are two sources:

For a basic overview of Linux security: Red Hat Enterprise Linux 6 Security Guide

https://access.redhat.com/site/documentation/en-US/Red_Hat_E...

Here is a blog post by someone who is protecting his laptop, for each security measure he says what and why:

https://grepular.com/Protecting_a_Laptop_from_Simple_and_Sop...

HN Discussion:

https://news.ycombinator.com/item?id=4018426