problem setting up gateway/router with iptables

[reed_young@rio.com]

configuration:
Etch amd64 with iptables & dhcp3-relay installed
Linksys router with DHCP server functioning
firewall script in /etc/init.d

goal:
Debian machine routes DHCP, DNS & Internet packets to Windows machine(s)
while providing port & packet filtering

situation:
Windows machine does not receive any packets back when attempting to
renew/establish IP address,  My iptables script looks right to me, so I
think my problem is with dhcp3-relay.  I haven't found much documentation
on this package, and not sure how to start/configure this service.  Thanks
in advance.