My sample samba config

[global]
    netbios name = Venetia
    server string = File Server
    workgroup = WORKGROUP
    announce version = 5.0
    socket options = TCP_NODELAY IPTOS_LOWDELAY SO_KEEPALIVE SO_RCVBUF=8192 SO_$
    interfaces = lo, eth0
    bind interfaces only = true

    passdb backend = tdbsam
    security = user
    null passwords = true
    username map = /etc/samba/smbusers
    name resolve order = hosts wins bcast

    wins support = yes

    syslog = 1
    syslog only = yes

[Public]
    path = /srv/public/
    browseable = yes
    read only = no
    guest ok = no
    create mask = 0644
    directory mask = 0755
    force user = administrator
    force group = administrators