Looking for OpenVPN Site to Site How To...

Is there a tutorial on how to create a site to site openvpn connection using 2 or more tomato routers? All of the documentation I have found seems to use the scenario of a computer being the client.

Is it possible to create multiple VLANS and have only one of the VLANS tunneled while the other does not? So depending on which SSID I connect to will reflect on what network services are available to the device.

Thanks.