Xbox360 Live Setup Hardware Advice. Options

[addyb]

Hi all, been a long time since posting on here but thought id just hide and read all the info on the new toy... not got one yet but will be doing in the new year!
Well all i want to know is what hardware i will need to enable me to get on xbox live using wireless.
My 360 will be downstairs and i have a 2mb broadband connection upstairs. Now do i just need to buy a wireless router and the wireless usb for the 360 and thats it? Im getting slightly confused as to the set up.
My broadband connection isnt wireless in anyway upstairs so do i just run my internet connection to the router and then then the plug the usb adapter into the 360 and that should pick up the connection from that point of view?
Help im going to order some hardware soon but dont want to get either stuff i dont need or fail to get the correct stuff.