Direct all your browsers to the Censornet box, and have it route through the m0n0wall. See their Bridging with IPCOP example:
http://www.censornet.com/support/diags.phpIf you wish, you can force all port 80 traffic through the Censornet box using some code like this in your config.xml on the m0n0wall where 192.168.1.x is the IP of your Censornet.
Search the mailing list archives for dansguardian, a similar product I believe.
<nat>
<rule>
<protocol>tcp</protocol>
<external-port>80</external-port>
<target>192.168.1.x</target>
<local-port>8080</local-port>
<interface>lan</interface>
<descr>redirect HTTP to LAN HTTP Squid Proxy server</descr>
</rule>
</nat>