Finally...Pottermore! My daughter has been waiting for over a year for this and finally it is starting to be rolled out. Pottermore is where you will find everything Harry Potter. Pottermore is more than a fan site - Pottermore is a transmedia experience where readers will be able to interact with and help the Potter stories come alive. Originally Pottermore was slated to open last October, but was delayed until now. They are rolling out "admission" to Pottermore slowly - so sign up now to get your invite in a few days.
Here is a great video by J,K. Rowling explaining Pottermore.
Have fun exploring Pottermore!