apt-get update
apt-get install samba smbclient
But, because you'll probably want to print, too, you'll need all of
the following (or so a website told me, and it worked):
apt-get install cupsys cupsys-bsd cupsys-client foomatic-bin
samba smbclient gs-esp a2ps
(You don't have to do that now -- if you don't want to print, or don't want to do it through CUPS, only bother with the samba and smbclient packages.