Add user as a unix user

Since I do not want samba users to have shell access, I usually add them without a shell:

adduser -c "Name of user" -s "/sbin/nologin" new_user

If you do want to give user shell access:

adduser -c "Name of user" new_user

Then use passwd to set the user a password.

Set Samba password

 smbpasswd -a new_user

Test Samba account

smbclient //smb-server/homes -U new_user
Enter new_user's password:
Domain=[SMB-SERVER] OS=[Unix] Server=[Samba]
smb: \> exit

Mapping on Windows

C:\Users\belminf>net use z: \\smb-server\share /persistent:yes
The command completed successfully.