Hi,
So I think it would be prudent to document this somewhere as it was the first thing I needed to do after installation completed on my Trusty 14.04 server box. Would also be worthwhile to document that install location is /usr/local/nagios.
sudo apt-get install apache2-utils
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Very happy with ease of install, thank you for sharing this!
cheers,
Rob