README: added notes

README.md

@@ -1,4 +1,18 @@
 nagios-plugins
 ==============
 
-A collection of Nagios Plugins I've written
+A collection of Nagios Plugins I've written for production unix environments.
+
+A few of the scripts like check_service.sh and check_volume.sh are designed to
+be run in heterogenous unix environments and should work on Linux, OSX, AIX, and
+the BSD's provided a bash or bash-compatible shell to interpret them.
+
+One way to run the plugins requiring elevated privileges is to
+configure sudo on each monitored machine to allow the nagios
+user to execute the plug-ins in the plug-in directory as root:
+```
+$ visudo # Use visudo to edit the sudoers file , or :
+$ echo ’Defaults:nagios !requiretty ’ >> /etc/sudoers
+$ echo ’nagios ALL=(root) NOPASSWD:/usr/local/nagios/libexec/∗’ >> /etc/sudoers
+```
+