I'm not that familiar with FreeBSD and have to search for answers on almost everything.
Some useful tips to help you start.
Search for a port
make search name=the pkg you want
whereis the pkg you want
The second command is not needed to run it into /usr/ports.
Flags for a port (for example amsn) If "nothing to configure" that means that have no flags
Install a port (for example amsn)
make install clean
ALWAYS run make clean to remove work folder before build it again!
Remove a package (for example amsn)
make deinstall clean
and the exactly output of command
pkg_info | grep amsn
Remove everything related on amsn
pkg_delete -xfri amsn
-x tells it to search for any packages with "amsn" in the name
-f tells it to forcibly remove the package, even if there are other packages that depend on it
-r tells it to remove dependent packages as well
-i tells it to ask you whether or not to remove the package, before actually removing it, in case there are some you want to keep
(From Phoenix post)
Update your ports tree
portsnap fetch update
Install the updates
Install specific updates (not all)
Clean your ports tree and useless distfiles
Copy a folder
cp -R folder (and not folder/)
On BSD folder
Find a package if is intalled on your system
pkg_info | grep the package you want to search
Load a module (for example linux)
Unload a module
Update your system
Upgrade your system
freebsd-update upgrade -r 8.1-RELEASE
Fix missing dependencies.
Notice: You must install portupgrade tool from ports first. Pkgdb is part of this tool.
I think this is the basics commands to save you from searching hours on google to find the right answer