Jason Holtzapple wrote this howto for graphing Nagios services with pnp4nagios. Using pnp4nagios is an easy way to graph services inside Nagios. This guide can help you set up pnp4nagios or migrate an existing graphing tool. Follow this link to view the howto.
http://tinyurl.com/mcskvz
Direct link: http://bitflip.net/presentations/ for people who don’t have a LinkedIn account.