In the move to the Gentoo wiki, I have updated and revamped most of our SELinux documentation. The end result can be seen through the main SELinux page. Most of the content is below this page (as subpages).
We start with a new introduction to SELinux article which goes over a large set of SELinux' features and concepts. Next, we cover the various concepts within SELinux. This is mostly SELinux features but explained more in-depth. Then we go on to the user guides. We start of course with the installation of SELinux on Gentoo and then cover the remainder of administrative topics within SELinux (user management, handling AVC denials, label management, booleans, etc.)
The above is most likely sufficient for the majority of SELinux users. A few more expert-specific documents are provided as well (some of them still work in progress, but I didn't want to wait to get some feedback) and there is also a section specific for (Gentoo) developers.
Give it a review and tell me what you think.