See two examples of cisco configs at http://william.leibzon.org/nagios/plugins/check_snmp_netint.pl
But these are for one service per port rather then multiiple ports together. For multiple ports you can use regex but I strongly recommend not trying to retrieve date more then 12 ports (there is actually limitation on how much data cisco will send in one SNMP packet and few switches allow to change this) You'll also have harder time creating full graphing config for multiple ports, but if you don't care and just want to see if port is up, it should be ok.
If you're doing one server per port, I recommend my plugin over Patrick's for cisco switches because of speed and caching optimizatons - when doing checks for each port separately you're basically doing same thing (retrieval of port names table to regex for right port) over and over and for monitoring of larger network this is significant issue. Plus there are cisco-specific extensions in the check_snmp_netint. Remember to change illegal macro characters as documented in plugin if you're using my examples; and in general I recommend you read documentation in the header of the plugin even though it is long. If you're interested I also have some simple bash scripts to generate nagios service configs for cisco switches.
Good luck with your nagios install and welcome to community!
