Instructions
Wireless
Turn on your Wii console and press the "A" button on the Wii remote to get to the main menu and click on the "Wii" button on the bottom left of the Wii menu.
Select "Wii Settings" and then click on the right arrow button to get to Page 2 of the Wii settings menu.
Click on "Internet" and then choose "Connection 1" Choose "Wireless Connection" if you want to connect your Wii wirelessly.
Select "Search for an Access Point." Your Wii will locate nearby wireless signals. Click on your wireless signal, then press "OK."
Enter your wireless password. Then click on "OK," "Save Settings" and finally "Yes."
Non-Wireless
Connect the Wii LAN adapter (sold separately) into the USB port on the back of your Wii console.
Connect an Ethernet cord from your modem to the Ethernet port on the Wii LAN adapter.
Turn on your Wii and press the "A" button on your Wii remote to get to the main menu. Repeat the steps in Section 1 with the exception of selecting "Wired Connection."