It will only become the official one if this is stickied. So for now, it's the unofficial thread.
I noticed that the "List of Released Dream World Pokemon and Attacks" thread was being cluttered with friend codes, and it was getting in the way of what the thread was supposed to be about. So, I have decided to make a thread to put it all in.
Here's what you need to know:
Originally Posted by Fat Serebii
In the main area of your Dream Island, you'll have a button which will allow you to check out all the islands in the area. These islands are based upon the friends in your Pal Pad. Once you and your friend have registered each other in your Pal Pad and had at least one WiFi encounter, their island will be accessible. Here, you can click their island and it will switch it as the main island. You and your Pokémon can now interact with your friend's area, allowing for the trade of items and to water their berries.
Also according to Serebii, watering your friends' berries gets you 10 Dream Points. Read more on the Dream World here
Anyway, this is the thread where you ask for each other's Friend Codes.
If there's anything I forgot to explain, please tell me and I will edit into the main post.
I don't have a copy of Black or White, so I obviously can't tell you my Friend Code.