i think this information will help troubleshoot:
lspci # will tell us the pci devices you have in your system.
lsusb # will tell us the usb devices you have in your system.
ifconfig # will tell us what network interface cards that are turned on you have on your system.
ifconfig -a # will list all network interface cards you have on your
iwconfig # will tell us which of your network interface cards has wireless capability
lsmod # will list the modules that are loaded on your system.
once we know the above information; these commands usually get people conected to their wireless routers:
sudo iwlist <network-card> scan # this will use the <network-card> interface (that from the iwconfig command above) and scan for wireless routers that are accessible.
sudo iwconfig <network-card> essid <your-router-name> # assuming no security (the access point names will be provided by the previous iwlist command).
sudo dhclient # will attempt to get ip-address, subnet mask, dns server information automatically from your router assuming dhcp is turned on on your router.