Adding new users to Samba

Hi all :

A quick question this time :

The scenario : A few windows workstations connected over the LAN 
to a Red Hat Linux 7 machine running Samba. This setup was configured
by soneone else , not me. The existing users can access the Linux 
machine as though it was a Windows file server. 

I have just created 2 new users on the Linux server

Question : How do I go about giving these 2 new users access to the Samba
                  services , so that they can browse the Linux file server from 
                  Windows as well ?