yep, the rule is everything begins with the supplyed VM cable modem (or *DSL modem if your using that type of connection ,most VM customers are cable though).
so, you plug the (Wireless)router into the CM through its WAN port, then everything on your LAN side plugs into the LAN ports of that router, weather it be wired or wireless, it doesnt matter (other than different speeds for LAN to LAN kit copying etc).
its the router that gives out all the LAN IPs your devices will use to get to the web, not the VM Cable Modem itself.
the (wireless)router just gets one single webside IP address for itself from the VM-CM, and passes all the data traffic through that IP to all the LAN side devices in your personal LAN.