You are on the right way , the ipwraw drivers will bring your wireless card into monitor mode , and therefore you cannot gain internet access.
To get your wireless card to surf the net aso you have to load the iwl3945 drivers.
If you want your card to sniff the air, type: modprobe -r iwl3945 && modprobe ipwraw
If you want to surf the net, type: modprobe -r ipwraw && modprobe iwl3945
Then follow one of the great tutorials (i.e by xploitz) how to connect your wlan card to an WAP with different encryptions.