Make Windows shares on the PC side. Once the PC side is configured, install at the very least SMBFS on the Amiga side, SAMBA as well if you would like 2 way sharing (see Odin's helpful post with links). Make sure to note the workgroup and all other relevant info on the PC side on those shares, because you'll need that info for SMBFS.
Setup SMBFS on the Amiga side with the info from the PC and you should be ready to roll.
Simple guide to Windows shares can be found at:
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/file_srv_create_share.mspxMore detailed info on Windows shares and netowrking can generally be found with Google, but that guide should be enough to get you up and running - as I said, make note of workgroup and share names, the IP of the PC, etc.
