linux - Block all but http traffic on a network interface

I've got two network interfaces on an Ubuntu machine which go out to two different networks but both have internet gateways.

I need to limit it so that any outgoing http requests it makes (ie through wget) only go through eth0 and all other traffic goes through eth1.

I dare say the solution might have something to do with iptables but I've no experience with it so would appreciate all help.