I got into FreeBSD by having to use the documentation, getting annoyed at bugs, and submitting patches to them. Then I submitted a token few ports. Later on I got involved in the security team because I had to use advisories and got annoyed with bugs and submitted patches, though I’ve since dropped off due to lack of time.
I have written a little for the O’Reilly Network. A version of that article is included in the book (an honest-to-goodness real paperback book) BSD Hacks by Dru Lavigne.
My ACLs article was translated into Turkish, if you are into that sort of thing. As part of BSD Hacks, it was also translated into German, Japanese, and Polish. There is a Russian version on a forum somewhere.