I’ve recently switched from pfsense due to the lack of support of some drivers in FreeBSD, and I’m still trying to find my way to the documentation here.
I saw plenty of places where to read, but some problems with them …
There’s the mailing list (are there any searchable archives of it?)
I also found this wiki: http://zeroshell.wikidot.com the people contributing to it are members of the project?
There’s also the forum
In any case, you did some serious job with this appliance!