Network address should be the IP you want the computer to use. On a private network, its usually somewhere in 192.168.0.# . You can change the 0 to a different number if you want your network to be different.
The Gateway address is the IP of the computer you want yours to go through to get to the internet. It's uaually 192.168.0.1, but doesn't have to be. It might also be one of the DNS servers.
Netmask is usually 255.255.255.0. Broadcast is usually 192.168.0.255.