Go to the middle receptionist at the top floor of the Pokemon center to receive your Pal Pad. She/he'll have you connect to the Nintendo Wi-fi network and then disconnect (it's automatic). The Pal Pad will then be located in the Key Items pocket in your item bag, where you can then open it up and register your friends as well as view your own code.
Edit- beaten.s
Andrex, for the OP, you should make images that match the season. Like the borders and stuff:
For example, in-game Autumn could be orange and have leaves on it. Winter could be white or something with snow on top.
Unless everybody's seasons are different then it wouldn't work...