There are two ways, one of them relevant to this list. The one not 
relevant involves getting the UNIX toolkit for Windows (can't remember its 
name) that allows you to mount NFS volumes.

The other way involves setting up a SAMBA server on the UNIX machine. If 
you are on a predominately windows network, then I presume you have a 
password server/domain controller? If so, then you want to amend the 
configuration file /etc/smb.conf.

There are graphical tools for doing this graphically. One tool called 
SWAT, when started, allows you to do this via a web browser. As I believe 
does webmin and linuxconf provides a different interface.

The manual way, would involve amending the relevant sections to this:

--
[global] *
netbios name = SERVER 
workgroup = WORKGROUP or DOMAIN_NAME 
security = USER/SHARE/SERVER/DOMAIN 
password server = POSSIBLY NOTHING

[DRIVENAME] 
path=PATH WHERE FILE IS LOCATED
guest ok = YES/NO
--

The line with the asterisk stays the same as it is. I'll explain what 
should be in each line (there are many more issues than this but I'll 
cover the basics).

netbios name is where you specify the name of the UNIX server as it will 
appear in Network Neighbourhood

workgroup specifies whether the server is part of WORKGROUP (the default) 
or some other domain name, which you can specify.

security - Use server if there is a password server on the network, use 
domain if you have a domain. share is used if you want to allocate a 
password per share, user is if you want the user to authenticate with a 
local username and password to view the files on any shares.

password server - if you specified the server security setting previously, 
then give the name of the password server here.


[DRIVENAME] Here you replace DRIVENAME with the name you want to give to 
this share so that it can be accessed from a Windows machine. It's 
pathname becomes \\SERVER\DRIVENAME

path is where you specify the directory you want to share (the directory 
where the file you want to access is located)

guest ok specifies that a non-authenticated user can view this share

The other thing you have to check is that the directory and its files have 
the right UNIX permissions to be seen or amended by the user accessing the 
share. Doing a chmod 755 on the directory, and ensuring the files have at 
least a 644 should be adequate for read access at least.

Now, starting up the server. Startup SAMBA (Most linux distributions seem 
to allow this via /etc/rc.d/init.d/smb restart - but after installed, a 
different UNIX server will have its own method)

You should now be able to see the machine on network neighbourhood. If 
not, then your sys admins may need to add the machine to the domain in 
Windows NT/2000. Now, your Windows machine can either go into Network 
Neighbourhood and when it finds the share, right click it and map it to a 
drive letter, or refer to it directly as I said earlier.

This is a very poor explanation of SAMBA, but if you need more help then 
post to here, after acquiring the samba package from www.samba.org.