Paperwork for ordering broadband wireless Internet

If you buy a computer, what do you need to do to get broadband-wireless connected? A friend told me you need all your visa, local registration etc. before you can get connected. Any ideas?

Normally, you just need your bank details, for the Direct Debit payments to whoever is your service provider (eg. Arcor), and a proof of address (I think I used my rental contract). That was enough when I signed up.

I just needed my bank details when I setup my connection with Alice but I did need my Anmeldebestätigung form in order to open the bank account. Most, if not all, ISPs will allow you to sign-up with them online so just pop into an Internet cafe and sign-up.