Your ISP should allow it... if you are worried about getting into legal trouble, you can contact them and ask how many computers you are allowed to connect wirelessly.
I would buy a router (802.11 G is the newest and fastest) and hook it up to the modem. Then, I would by a few wireless reciever PCI cards, and put them in the computers you would like to connect. Be sure they are either 802.11g or 802.11b if you use an 802.11g router.
You will also want to buy a router with a built in firewall, enable WEP, MAC, and disable TCP/IP and enable NetBEUI.
Hope this helps, and if you need any other help, post back!
I would buy a router (802.11 G is the newest and fastest) and hook it up to the modem. Then, I would by a few wireless reciever PCI cards, and put them in the computers you would like to connect. Be sure they are either 802.11g or 802.11b if you use an 802.11g router.
You will also want to buy a router with a built in firewall, enable WEP, MAC, and disable TCP/IP and enable NetBEUI.
Hope this helps, and if you need any other help, post back!