 I added some external links but someone deleted two as too general. Emmerson and melissa from leaky cauldron and mugglenet were specifically invited to interview JKR just after half blood prince was published. She rates them highly and has given her 'best website' award to them. So they are good references for anyone wanting to know more. The two specific links are to the opening page, but anyone linking there could then find out more. There are many pages on each which would be relevant, and also changing, so I do not see the sense in listing all possible pages from the website. Wiki recommend citing sources and places for further information.  