So I thought I'd get smart and set up a Linux machine as the firewall for my Win machines to Comcast. Problem is, it doesn't work! Please help!

Here is what I've done:
1] Install Redhat 9 as server (this means I don't have to recompile kernel, right?)
2] configured 2 ethernet cards
3] eth0 does see the internet
4] configured DHCP for Win machines
5] eth1 leases ips for the Win machines
6] ping from Win to Linux and Linux to Win works fine
7] in the "network" file, forward_ipv4=yes
8] when Win machine trys to ping internet or start up IE I get nothing but time out or the typical IE error page about can't find server or DNS error.

Initially, I had tried to set up the Linux machine as the DNS but that didn't work. Then I thought I'd just get the thing working first by putting the DNS server of my local Seattle area DNS in the "dhcpd.conf" file instead. Nothing still. So, I'm not sure if I've missed something along the way or have a simple missed command somewhere... and I'm not sure where to go from here. Any help would be greatly appreciated!