Below are links to more SE Linux related material. Please read the NSA white papers.
The NSA's official SE Linux site is at https://www.nsa.gov/selinux
The official SE Linux FAQ is at https://www.nsa.gov/selinux/info/faq.cfm
NSA published papers, technical reports and presentations can be found at https://www.nsa.gov/selinux/info/docs.cfm
The NSA run a mailing list for discussion of all things SE Linux. Follow the instructions at https://www.nsa.gov/selinux/list.html to subscribe. The same URL describes how to obtain list archives.
The SE Linux project at Sourceforge is located at https:/sourceforge.net/projects/selinux.