In order to use Wine you need to build and install a new kernel with
options USER_LDT, SYSVSHM, SYSVSEM, and SYSVMSG.

The port also installs some of Wine's doc files which describe additional
things that are not in the manual pages, see
  %%PREFIX%%/lib/wine/documentation.
There are more in the source tree but the others are only useful in
conjunction with the rest of the source tree, and then you can as well
look at them there.  (If you just installed this as a package and do not
know how to use the ports system to have it fetch and extract the source,
have a look at <http://www.freebsd.org/handbook/ports.html>.)