You can use your router as an access point and the DHCP, DNS, and filtering would manage pfSense. It should be
lSP modem–-(connects to the WAN port of the pfSense box)----pfSense-----(connects to the LAN port of the router)----Router(netgear,linkys,etc)
If you want more out of your WIFI i recommend flashing the router(access point to DDWRT)