Well, I have an Xbox360 Elite and my friends were saying that some Xbox's need an 'Adaptor' in the back.. I was wondering if I would need one? I bought this Xbox last year in December if that means anything, thanks.

Okey, to get yer xbox to connect to live, you either need a wireless adapter, or just plug in an internet cable in the back of the console, buy yourself a month gold on the xbox, "wich will give you automaticly new gold every month for a pretty decent fee"
or buy yourself 3 months gold at the game store. (3 months is the shortest time you can buy gold for in the stores)

Or you just buy yourself a xbox slim and it will connect to your internet as soon you plugged it in ;)
wont need any adapter or cable.
But as said, need gold.

And the first month of gold is free if you choose "not" to go gold when you're done setting up your online identity, gamertag, email etc.

Ok. If you don't want to spend money on an adaptor you could use your laptop.
Then you have to buy xbox live depending on how many months you want.
And finally enjoy online gameplay.