TomatoUSB

I will try to attach an image to show the network layout.
Basically we have two separate networks. Each one has its own dedicated internet connection. I would like to be able to route between the 192.168.10.x network and the 192.168.20.x network.
Each router is running TomatoUSB. One router is a Linksys E3000, the other is an Asus RTAC66U.

Some of the terminology in the UI for TomatoUSB doesnt seem to make sense.
I would like to enable one of the Ethernet interfaces on the Asus router and connect it to one of the switches in the 192.168.20.X network. The two routers are not close enough together to run a cable between them, so the only thing I can do is connect the Asus router to a switch in the 192.168.20.x network.

What I would like to know is what do I need to do on both routers to enable it so that the two networks can route to each other?

Since I am a low ranked user, I can post the link directly.
It can be found out:
www dot gliffy dot com/go/publish/image/8136989/L.png

What this guy has asked for is almost exactly what I am in need of help with. The picture below is my configuration and I am looking for the routing commands that are needed for each of the routers and how to enter them. The Netgear 3500L running Shibby Tomato 1.28 is acting as the bridge between the subnets. So far I have connection one way using the WAN port and one of the LAN ports. The 3500L being set in Gateway mode. I know this is wrong as the NAT is not allowing connections both ways. I need to know which ports to use on the 3500L and the routing commands in order for both subnets to be able to see devices on either subnet in windows and communicate to the DLNA server in one subnet and the other subnet communicate with the Lan Printer.

ok so I had a picture to make it easy to see what I want to do but someone decided that first time posters cant post links! So now my post is pretty much pointless! Useless forum settings!

Any help much appreciated.
Thanks
Cougar