Nagios 3.0.3 Help

Greetings:

I just completed my Nagios 3.0.3 setup and everything works grand, but I do a few bugs that I need some help with. First is I am not receiving notifications. I imagine that I must configure Postfix… Any suggestions for help with the config is appreciated. Second, I am receiving text on my status map, it appears to be some sort of status check output. Regardless, any ideas how eliminate it. Next, Under Tactical Overview, when I toggle a service I receive the error message “Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ for update”. I checked all the permissions and everything appears to be correct. Last but not least, my Nagios Checker will not display any notifications. I still have the server as an IP address. I have not yet setup DNS for this server. Would this cause a problem with Nagios Checker…? Any and all help/suggestions are appreciated.

Thank you in advance.

I followed this manual and it worked fine for me.

fannagioscd.sourceforge.net/drupal/?q=node/10