This Section lists each of the options that can be used in a Samba configuration file, which is usually named smb.conf.   Most configuration files contain a global section of options that apply to all directories(shares), and a separate section for various individual shares.   If an option applies only to the global section, [global] appears before its name in the following reference section.   Any lists mentioned are space-separated, except where noted.

Information below is a subset from the O'Relly pocket reference and I have only included the most common terms from the said reference and as follows:

admin users = user list 

   allowable values: user list

   default : NULL

   specifies a list of users who will be granted root permissions on share by Samba

allow host = host list 

   allowable values: list of hosts or networks

   default : NULL

   specifies a list of machines that may connect to a share or shares.   If NULL, any machines can access the share unless there is a host deny option

[global] allow trusted domains = boolean 

   allowable values: YES, NO

   default: YES

   allow access to users who lack accounts on the Samba server but have accounts in another, trusted domain.   

   Requires security = server or security = domain 

[global] auto services = share list 

   allowable values: list of shares

   default: NULL

   specifies a list of shares that will always appear in browse lists, also called preload 

available = boolean 

   allowable values: YES, NO

   default: YES

   If set to NO, denies access to a share.   does not affect browsing functions

browsable = boolean 

   allowable values: YES, NO

   default: YES

   allows a share to be announced in browse lists.   also called browseable 

create mask = octal permission bits 

   allowable values: octal values from 0 to 0777

   default: 0744

   sets the maximum allowable permissions for a new files(e.g. 0755).   see also directory mask.   

   To require certain permissions to be set, see force create mask and force directory mask.

[global] deadtime = number 

   allowable values: number of minutes

   default: 0(zero)

   specifies the time in minutes before an unused connection will be terminated.   

   Zero(0) means never.  used to keep clients from tying up, server resources for

   long periods of time.   If used, clients will have to auto-reconnect after the specified period of inactivity.   

   see also keepalive 

directory = pathname 

   allowable values: full Unix pathname

   default: varies

   sets the path to the directory provided by the file share or used by printer share.   

   If the option is omitted, set automatically in the [home] folder share to the user's home directory;   

   Otherwise defaults to /tmp honors the %u (user) and %m (machine) variables. see also path.

directory mask = octal permission bits 

   allowable values: octal values from 0 to 0777

   default: 0755

   sets the maximum allowable permissions for newly created directories.   

   To require that certain permissions be set, see the force create mask and force directory 

mask directory mode = octal permission bits 

   allowable values: octal values from 0 to 0777

   default : 0755

   synonym for directory mask

[global] domain master = boolean 

   allowable values: YES, NO

   default: NO

   makes the server become a domain master browse-list collector, If possible, for the entire workgroup or domain

force create mask = octal permission bits 

   allowable values: octal values from 0 to 0777

   default: 0 (zero)

   Takes effect when a user on a Windows system creates a file that resides on the Samba server.   

   This option ensures that bits will always be set on the file when they are set in this mask.   

   used with the create mask configuration option, above and also called force create mode 

force directory mask = octal permission bits 

   allowable values: octal values from 0 to 0777

   default: 0 (zero)

   takes effect when a user on a Windows systems creates a directory or folder on the Samba Server side.   

   This option ensures that bits will always be set on a directory when they are set in this mask.   

   used with directory mask and also called force directory mode 

guest account = username 

   allowable values: username

   default: NULL

   sets the name of the unprivileged Unix account to use for tasks such as printing and for accessing shares marked with guest ok 

guest ok = boolean 

   allowable values: YES, NO

   default: NO

   If set to YES, passwords are not needed for this share (for particular shares only).   requires that Public to be set.

[global] keepalive = number 

   allowable values: number of seconds

   default: 0 (zero)

   sets the number of seconds between checks for a crashed client.   

   The default of 0 (zero) causes no checks to be performed.   setting SOCKET OPTIONS=KEEPALIVE will turn on checks every four(4) hours.   

   A value of 3600 (every 10 minutes) is recommended if you want checks more often than every four(4) hours.

[global] load printers = boolean 

   allowable values: YES, NO

   default: YES

   loads all printer names from the system's printcap file into the browse list.   

   uses configuration options from the [printers] section

[global] map to guest = value 

   allowable values: Never, Bad User, Bad Password

   default: Never

   If set to Bad User, allows users without accounts on the Samba server or system to log in and be assigned the guest account.   

   This option can be used as part of making public shares for anyone to use.   

   The default setting of Never prevents users without accounts from loggin into the Samba Server.

printable = boolean 

   allowable values: YES, NO

   default: NO

   Sets a share to be a print share.   required for all printers.   Synonym for print ok 

[global] printcap name = pathname 

   allowable values: full Unix pathname

   default: /etc/printcap

   Sets the path to the printer capabilities file used by the [printers] share section.   

   The default value changes to /etc/qconfig under AIX and lpstat on System V.   also called printcap 

public = boolean 

   allowable values: YES, NO

   default: NO

   If YES, passwords are not needed for this share.

[global] security = value 

   allowable values: share, user, server, domain

   default: user

   Sets the password security policy.

   If security = share, services have a shared password, available to everyone.

   If security = user, users have (Unix) accounts and passwords.

   If security = server, users have accounts and passwords and a separate machine authenticates them for Samba.

   If security = domain, full NT-domain authentication is done.

valid users = user

   list allowable values: list of users

   default : NULL (everyone)

   specifies a list of users that can log in to a share.

[global] workgroup = name 

   allowable values: workgroup name

   default: compiled-in

   Sets the workgroup to which things will be served.   Overrides the compiled-in values.   

   choosing a name other than WORKGROUP is strongly recommended

writable = boolean 

   allowable values: YES, NO

   default: YES

   Antonym for read only; writeable and write ok are synonyms

write list = comma-separated list 

   allowable values: comma-separated list of users

   default: NULL (everyone)

   Specifies a list of valid users that can/are given read/write access to a read-only share.