What's the best way to monitor traffic?
I would like to be able to know who is using what amount of the network bandwidth at any given time. I tried bandwidthd, but it only shows traffic after it
Did you look at anything pflowd/ntop/darkstat/snort…whatever apps that capable of tracking.
You can try monitoring traffic via SNMP, running PRTG or MRTG apps on a separate server and definig there sensors that point to your pfsense server. Of course you have to enable SNMP in pfsense.