CNA Zone: http://cnazone.com/. CNA Zone clients are able to work on and obtain unlimited credits each year. In order to do so, all they need to do is to pay $24.99 for a yearâs membership to CNA Zone. An additional deal allows CNAs to receive one CEU course for free. Students will have the ability to access their training no matter where they are located and no matter what time or day of the week it is at the time.