In order to use wine you need to build and install a new kernel with
options USER_LDT, SYSVSHM, SYSVSEM, and SYSVMSG.  Before you do that,
you may want to apply the patches in %%PREFIX%%/lib/wine to your
kernel sources, see the README.patch there.

And the port now 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 don't know how to use the ports
system to have it fetch and extract the source for you have a look at
<http://www.freebsd.org/handbook/ports.html>.)