You shouldn't need to do that much , as they should both be on different subnets , so they won't interfere with each other . The ethernet cable from port 1 on the modem should plug in to the WAN port of the wireless router , then from port 1 on the wireless to the ethernet port on the PC . Access the wireless router by typing in the IP address ( usually 192.168.1.1 for Netgear ) , there will be a wizard that will first of all find the internet connection , follow that through .
Make sure that wireless access is turned on ( some ship with it disabled ) and have DHCP on both . You'll only have success using an ethernet port rather than the WAN port if DHCP is disabled on the wireless router , you only need to do this if they are both on the same subnet ( both 192.168.0.1 or 1.1 ) . Save all the settings , temporarily , without any security , disconnect the ethernet cable to the PC and try connecting wirelessly .
If that works , first of all change the SSID from the usual Netgear to something more pertinent to you , then go about setting some wireless security , preferably WPA , get a decent key click here for a random WPA generator and cut and paste the result to wordpad so you can accurately enter it in to the relevant place in the router ( cut and paste again ) . Save all settings again , and re-try wireless access , enter the security key and all should be well .