I am trying to access the internet on a windows box through my RH 7.1 box. My RH box is has 2 NIC's, one connecting to a cisco router (it does NAT), and the other connecting to my windows box. Eth0 is configured as follows IP=10.0.0.3 NET=255.255.255.0 GATEWAY=10.0.0.1, this NIC connects to my router. Eth1 is configured as follows IP=10.0.1.1 NET=255.255.255.0 and it connects to my windows box. My windows NIC is set up as follows IP=10.0.1.2 NET=255.255.255.0 GATEWAY=10.0.1.1. I can ping both NIC's from my windows box, but I can't ping the gateway of eth0 (10.0.0.1). Can someone please help me out or push me in the right direction. Thanks for any help...

Have you setup the correct iptables or ipchains?
If you use iptables, make sure to disable ipchains from starting up. RH7.1 seems to load both out of the box, which i found not to be good.
Also, make sure your default gateway on the linux box is 10.0.0.1 (your router).
also, run
$# route -n
on the linux box to make sure all the correct routes are setup.

amoung the other things like ipchains or tables you also need to set up forwarding

[root@echo ipv4]# cat /proc/sys/net/ipv4/ip_forward
1
-------------------------------------------------------------
if this gives you a 0 then do this command

echo 1 > /proc/sys/net/ipv4/ip_forward
-------------------------------------------------------------
and the network file

[root@echo ipv4]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=echo
GATEWAY=150.10.128.5
GATEWAYDEV=eth0