In "Finder" (click on the desktop) click command-k (command is the one with an apple logo and pretzel on it). This pops up the "connect to server" dialogue. In here type the URL for the share you want to access, e.g.
smb://fqdn_for_server/share/
Note that windows notations of \\server\share will not work, it has to be in Internet URL format, it's largely a \ for / swap, but you'll need to use the FQDN for the server and not a WINS hostname. Having working DNS is crucial.. although in theory that's statements' correct for AD too.
You can go a lot further and fully integrate Tiger with AD for authentication if you want, but as long as the users shortname in OSX (e.g. jdoe might be the shortname for "John Doe") and password match their equivalents in Windows it should all just work. If they don't.. you can change the OSX shortname in the NetInfo Manager but that's getting a little complex if you don't know OSX - the "idiot's guide" books are a good start if you're a windows person.
Once you get it working have a look at
www.macosxhints.com for a CLI preference that will stop your boss littering the windows fileserver with .DS_Store meta-data files. The site
www.macwindows.com is also useful for bug info and hints on Mac integration with Windows networks. The bugs are usually with Windows I might add..
SDB