iPhone not connecting to Linksys router / modem.
1. Ensure Wireless is enabled under Settings > Wi-Fi and turn it ON.
2. Join a network by selecting Settings > Wi-Fi.
3. Select the network you would like to connect to.
4. You may need to enter a password, then select Join.
Now enjoy the Internet. You will know if the device is connected to a wireless network if the Wi-Fi logo appears on the top bar of the screen.