Some documentation for

rc.d system

Many packages provided by this Linux system provide rc.d scripts that can be used to start, stop, restart, show the status (if running), sometimes reload, and sometimes other features. Usually the rc.d script is enabled by setting a variable to "yes" or "on" in your /etc/rc.conf file. The rc.d scripts are installed to /etc/rc.d/ directory. Run the script with the "rcvar" argument to see what the variable may be.

A daemon-writer's guide to NetBSD's rc.d system, http://www.newsforge.com/article.pl?sid=04/01/09/2159213
The Design and Implementation of the NetBSD rc.d system, http://www.mewburn.net/luke/talks/auug-2003/
NetBSD Guide: rc.d System chapter, http://www.netbsd.org/guide/en/chap-rc.html
The NetBSD rc.d System, http://www.daemonnews.org/200108/rcdsystem.html

pkg_* tools

pkg_info -- used to list installed packages, package descriptions, requirements (dependencies), etc.
pkg_add -- used to install a new package or upgrade a currently installed package; can install from download site; and installs dependencies automatically.
pkg_delete -- uninstall a package; and also recursively uninstall a package and any packages depending on it or install a package and any of its requirements that aren't used by other packages.