First of all, Flashback, WELCOME to forums ! Stay here and we'll allways find some solution. You'll find best bunch of people in here, and whenever you need help, there will always be someone ready to help.
Regarding your question, I'm not 100% sure, but I think and I'm 99,9% sure that you can't do that with Home Edition. You have to purchase Server Edition. See here:
http://www.avast.com/eng/purchase/network_solutions/index.htmlOr, if you're "short" on money, why not installing avast! Home Edition on all computers in your little private network ? It's very easy and very functional. I have two machines, one is running Professional Edition (Thanks Alwil, I'm thankful till I die), and another one is protected with Home Edition. Both of my PCs are connected through my 4 port router/firewall.
Hope this clears that little bit...
Cheers !