XServer Networking

HELP! HELP! HELP!
I am desperately trying to network 2 iMacs & 2 eMacs with a G5.

I want the G5 to control the network (I have the OS X Server 10.3 on it). Control includes centrally holding all user profiles & user files, the firewall, virus software, standard software & internet connection.

Both iMacs/eMacs are running Standard OS X 10.3. In addition, I have an Airport Base Station.

HELP! HELP! HELP! I have tried everything! Read countless websites & books. Everything ends up not making sense or with a deadend.

I was told Mac's were as easy to use as a toaster, disillusioned

1 x Apple Mac G5: OS X Server 10.3 (Fully Updated)
2 x Apple iMac: OS X 10.3 (Fully Updated)
2 x Apple eMac: OS X 10.3 (Fully Updated)
Airport Extreme Base Station