voy a comezar por cambir la carpeta de documentos al directorio que es visible desde la web. y segundo voy a editar el smb.conf como me recomiendan, de todas maneras aqui va el smb.conf del servidor:
[global]
workgroup = MYGROUP
server string = Samba Server
printcap name = /etc/printcap
load printers = yes
cups options = raw
log file = /var/log/samba/%m.log
max log size = 50
security = user
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
dns proxy = no
idmap uid = 16777216-33554431
idmap gid = 16777216-33554431
template shell = /bin/false
winbind use default domain = no
[homes]
comment = Home Directories
browseable = no
writable = yes
[printers]
comment = All Printers
path = /var/spool/samba
browseable = no
guest ok = no
writable = no
printable = yes
[img]
comment = Imagenes
path = /var/documentos
valid users = apache
public = no
browseable = yes
writable = yes
printable = no
Esta tal cual como el original, lo que no aparece es porque esta comentado.