Integrating Linux in a Windows Network

I have a Windows Network, that is composed of Windows NT 4 servers and a variety of Win2k and 98 workstations.
I recently setup Slackware 7.1 on 2 machines, they are working together in a fine way, share and mount directories between them perfectly, but I don't know how to make windows machines map folders on them (I can ping the 2 Slackware machines by IP addresses and hostnames from all the Windows workstations). Is there any missing software or steps that I have to make?
By the way, I haveno idea about Linux