The file system type is either cifs or smbfs if we are talking about Windows shares. Smbfs for sure if we are using Win98.
The correct mount command would be "mount -t smbfs -o username=[windows user name],password=[windows password],workgroup=[windows workgroup],uid=[linux user],gid=[linux group] '//[ip address of the win98 box]/[shared folder name]' /mnt/win98"
Uid and gid tell the user and group the mounted share belongs to. You need to specify these if you wish to have access to the mounted stuff as a mortal user. We cannot really assume 500 here, since users/groups may be different on different systems..