If the Wi-Fi symbol is shown in the notification area you have successfully connected to a wireless network.
If you could not see the mobile network data indicator please contact you network carrier for support.
Note: If you could not find "Mobile networks" checkbox (e.g. on Samsung Galaxy S) please contact you network operator for support.
Manage Connections -> Set Up Wi-Fi network-> Scan For Networks
Select a network from the list and follow the instruction to set up the network for the device.