Polling eth0?

[Dennis Craven]

Hello,

I intend on writing a small application that monitors incoming/outgoing
traffic on eth0, and recording the bandwidth usage with monthly
totals etc..

Where would be a good place to start in regards to connecting to 
eth0 and reading such data? I am somewhat familiar with Python, and
its simple constructs, but I'm not so familiar with this network 
aspect.

Any particular modules/examples/documentation/tutorials that I should
start out reading?

Thanks,
~djc