You don't say how far you got with this when it asked for a password did you put in the WEP key for your router - usually found on the bottom of the router?

You don't have to have a wifi connection to use the kindle or register it - this can be done using the 3G capability - if your kindle has this. To do this:-

You can register your Kindle online or straight from the device itself.

To register your Kindle online log on to Amazon and go to your account.

Go to the Manage Your Kindle page and click "Register a Kindle" from the left side.
Enter the 16-digit serial number of your Kindle (Tip: It starts with "B00E").
Click on "Register".

To register your Kindle on the device:

Press the Home button, then press the Menu button and select Turn Wireless On.
Press Menu again and navigate to "Settings" using the 5-way controller; press to select.
If you received Kindle as a gift, and the person who gave it to you is listed as the

"Registered User," select "deregister." Select "register."

If you have an Amazon account:

Enter the e-mail address and password of your Amazon.co.uk account. Navigate to "submit" using the 5-way controller; then press to select. Your name will appear as the "Registered User" when registration is complete. If you do not have an Amazon account: Navigate to "create account" using the 5-way controller; then press to select. Follow the instructions on the screen. Your Kindle will be automatically registered.

I used this when registering mine. I then just have to go on to Amazon - choose my books - click on add to basket - you should be asked whether you want this to be sent to your Kindle or to your PC (you can have both options, I have them sent to a laptop also - I did this before I bought the Kindle to see what the books were like and they now get sent to a laptop so I have two copies). Click on your Kindle - turn on your Kindle, go to menu, settings, at the top you will have an option to turn on wireless - this will be the 3G network - your books will then be sent to you. This way possibly is a bit slower than having them sent via your wifi router but mine come immediately. Also I have downloaded them when abroad on holiday using this method - even in the mountains!

Here is the Amazon link for troubleshooting.