How to Connect One 3G Router to Another establish ideal Network?

[Nick]

You have to connect the routers together using their LAN ports, you have to have the WAN port of the second router not connected. When you do this then there is only one LAN for both routers.

You also have to make sure the management addresses of the two routers are unique.

It doesn't matter which DHCP you leave enabled, as long as it's only one of them. If one router does static DHCP and the other doesn't, then use the one that does, static DHCP is too useful and makes your port forwarding easier without having to assign a static address.

The port forwarding has to be done on the first router, as it is the one connected to the Internet. Port forwarding doesn't care about DHCP, it only cares about IP addresses.

If you want to have both WiFi access points operational, they have to have separate SSID's and need to be set up to use different channels.