Create a user for samba only (CLI)

1. Create a user on the server:

sudo adduser --no-create-home --disabled-password --disabled-login sambausername

2. Add that user to samba (you'll be asked to type a password):

sudo smbpasswd -a sambausername

3. Create a share by editing /etc/samba/smb.conf. For example, you can add something like this to the bottom:

   [share name]
       comment = whatever
       path = /path to share
       browsable = yes
       read only = no
       guest ok = no
   

4. Now is a good idea to restart samba:

sudo service smbd force-reload

5. Go to the client machine and try to access the share with the username and password you've just set up.

A Note about adding users on Samba version 4.x

Unlike Samba version 3.x and earlier, Samba version 4.x does not require a local Unix/Linux user for each Samba user that is created (if it is connected to another authentication source, like Active Directory).

The command is as follows for adding users into Samba Active Directory

samba-tool user add USERNAME-HERE

Please see Samba AD DC howto for more info

Answer Extracted from Cyberciti

To verify your Samba Version just user the command

samba -V

Example Output:

Version 4.3.11-Ubuntu