Connect the router using network cable...

and get into web based setup/configuration. If you cannot get in, DHCP server may not enabled in the router. Manually set an IP address for your network card and connect to the router again.

Make sure broadcast SSID is enabled/selected or your laptop won't be able to find the router. You can later disable it for better security once your laptop is configured with your wireless network.
If it fails, pick another channel and try again.
If the your router can be seen but no connection (no IP), make sure DHCP server is on and check security settings (encryption) on both laptop and router.

All above changes made on router may require restarting your router.

Or you can use NetStumbler to scan all available wireless access points. Yes, it can scan and find those with SSID broadcast off.