I'm curious about SELinux, but find its learning curve pretty steep, especially since I want to know how things are handled from the lowest level up.

I found some on-line resources on-line, but these are quite dated, so I wonder how valid they are today.

What would be best books and current on-line resources for one to use to learn about it ? I don't want to make my quest much heavier than it needs to be wearing my eyeballs through a mountain of obsolete stuff...