Suggestion:
The first thing you need to do is connect your xbox to a broadband connection. If you already have internet like comcast cable internet, you'd just take the plug going from your modem to your pc, and unplug it from your pc and put to your xbox.
You could of course get a router so you're not unplugging stuff all the time. The router will split your internet up so you can use your internet on more than one thing at the same time. And if you get a wireless router, you could just buy an adapter for your xbox so you don't have to run a cord from your router to your xbox.
To install a router, you'd just plug your modem into it and follow the instructions on the box.
For xbox live, you'd have to use a credit card or pre-paid card to pay for the account. You can buy pre-paid cards at a lot of game stores and online in many different increments.
And you'd just follow the instructions on your xbox to set a gold account.
