I've done a little more investigation. So I'll try to be more specific with my questions.
I've located a section in my Apache httpd.conf file that appears to control access. I'm pretty much using the Apache conf that came with Nagios.
The httpd.conf contains this:
AuthName "Nagios Access"
AuthUser File ........
Do I change some of this to make Nagios viewable to everyone to everyone without logging in?
I also see a "use_authentication=" statement in my Nagios cgi.cfg. I have it set "=1". Should I change that to "=0"? Or will that open up the privileged functions that I wish to be controlled by privileged users?