As before, need to know a little more about your setup but I assume you have a wireless hub with WEP or PSA security, 'cos you'll need the key to input into the Wii. I assume you've done that & have a conn'n established to your wireless hub (or can be wired). If not its Wii Options (bottom left main screen), Wii settings, 2nd screen (right arrow) to get Wii Systems settings 2 list, then select Internet. You then get connection settings and essentially complete the 1st entry for your wireless conn'n.
Its a while since I did it but I do remember it is pretty straight fwd if you've set up any laptop wireless before.
What is likely holding you up now/then is the fact you need to purchase the Internet channel s/w on your Wii. To do that you have to buy some Wii points. Go to the Wii shop and add points. 'cos you've got the internet conn'n above the s/w already supports card purchase of points (funny how that s/w is there already isn't it......?). Min'm is 1000 points for £7, I think. It costs 500 points for the Internet channel. Purchase, download & then you get it as a main menu item.
Away you go.....
MSL, May 2009