- The Official J.K. Rowling Website. (text only version).
- The Leaky Cauldron. (a HP-News blog).
- The Hogwarts Professor.
- Everything there is to know about Harry Potter and the Half-Blood Prince.
If you haven't seen Azkaban and haven't read the book, I strongly recommend reading the book. While director Alfonso Cuarón did a fine job, he did leave out a number of key points and scenes -- my daughter and I figure it would've only taken another 2 to 5 minutes of movie time to have added these.