“Members only” section of a WordPress site – self signup and no backend access

Take a look at theme my login which covers:

• Redirect users upon log in and log
  out based upon their role
• Require users to be approved and
  confirm e-mail address upon
  registration

and in order to create you member only pages you can use your regular pages and simply add this function to your theme’s functions.php is_user_logged_in()

add_shortcode('member_only','member_only_shortcode');
function member_only_shortcode($content){
    if ( is_user_logged_in() ) {
        return $content;
    } else {
        return __('You must log-in to see this content ');
    }
}

usage: [member_only]content to show your members[/member_only]