This article 10 Tips for Wireless Home Network Security is a good starting point for securing your wireless home network.

1. Disable the SSID broadcasting. See: How to disable service set identifier (SSID) broadcasting on your wireless router
2. Accept specified MAC addresses only. See:
   • Enable MAC Address Filtering on Wireless Access Points and Routers
   • Filter MAC Addresses To Secure Your Wireless Network
3. Use the highest avaiable encryption. If you have WPA2/AES, then that would be the one you should use.

 This article provides a basic instruction Wireless Router Configuration.