What does ifconfig -a give you?
If you can ping I would think that TCP/IP is up and running, if you cant see the machine from the network then it looks like a samba problem. You say that apache won't serve pages are you using //machine-network-name? If so, if you can't see it from the network, your request won't reach it. Try //IP-address see if that works, is so samba would apear to be your culprit