suse 7.0 firewall help

Hi I can't configure suse 7.0 to run a simple firewall. HELP! Can someone list what I have to do in English please to configure a firewall on a box with a ppp dialup and a nic for the internal network (eth0) I need masq. We are soon to get a 10Mb internet access so then it will be 2 nic's Is the setup a lot different from the above? At the moment when I say yes to ip_forward and/or start firewall in rc.config, I get lots of permission denied statements on boot. Many thanks ================================================================== Dave York