To setup the wireless connection on the Raspberry Pi you will need to:

• Buy a USB wireless adapter such as this one
• Plug it into the USB slot on your Raspberry Pi
• Configure it to join a wireless network

To configure the Raspberry Pi to connect to a wireless network perform the following steps:

Login to your Raspberry Pi either with a keyboard and mouse connected by pressing ‘startx’ at the prompt, or connect remotely using VNC viewer as shown in this post.

The first thing to do is double click on the wireless config item on the start screen:

Double click on the wireless configuration icon in order to add password details for your wireless network.

 This will bring up the following prompt:

Clicking on wireless config on the Raspberry Pi desktop brings up this page.

You then need to click on the Scan button:

On the desktop click on Scan to show the available networks.

Double click on the network you want to connect to which should bring up the following screen:

Once you have double clicked on the wireless network you want to join this screen should show.

You can then enter your password into the PSK field and click Add. Note that you may need to change the encryption method to the one that your wireless network uses:

Your password can be entered in the PSK field.

From a terminal you should now be able to ping google:

Checking you can ping google with the wireless network setup.

You can also inspect the network connection by typing the following into a terminal:

sudo /sbin/ifconfig

This should give you a screen similar to the following:

Output screen showing the setup on your interfaces.