I need Help setting up port forwarding for my foscam FI8910W.

I am currently on Mac OS X 10.7.5. My ISP is verizon FIOS and I have an Actiontec MI424WR router with the wireless turned off. I have an AirPort Extreme running from the actiontec router for my wireless network. First of all I need to know if I should plug the Foscam into the actiontec router or the Airport Extreme? Then I need to know if I should set up the port forwarding on the Actiontec or the Airport Extreme. Lastly I need detailed instructions on how to set up the port forwarding. Hopefully someone has a solution. Thanks