Okay, the solution here is simple, if I am to understand your problem correctly.
You need to make the two routers be aware of each other and route their subnets to each other.
DO NOT toy around with the DHCP settings or the clients -- networking should be handled by whatever you are using as routers.
IE:
IGW Network: 192.168.0.0/24
OGW Network:192.168.1.0/24
on the IGW router, it has something like:
0.0.0.0 routes to 192.168.0.1 (orwhatever your internet gateway is)
It also needs to have:
192.168.1.0/24 routes to eth0 (or however it connects to OGW)
OGW needs to have:
0.0.0.0 routes to eth0 (or however it connects to IGW)
Also, you could play around with RIP, which comes with most OSes. I suggest searching google for that information though.