There are several free websites about Harry Potter.
There are none. That's why we have cinemas.
At Harry Potter.com
The Harry Potter and the Philosopher's Stone website no longer exists. Warner Brothers updated the website with the release of each new movie. With the end of the series the website remains as Harry Potter and the Deathly Hallows.
Legally, you can't find Harry Potter audiobooks for free. However there are loads of free podcasts to listen to!
You can find the answer on a website called Fanfiction. There are fic where people write about Harry Potter reading Harry Potter and The philosopher's stone and so on...
You can watch all the Harry potter movies on watchonlinemovieshub.com in HD quality.
harrypotter.com
You cannot legally download any of the Harry Potter books for free.
There is an online quiz called "Who is Your Harry Potter Husband?" on the quiz website PlayBuzz.
Answers.com has summaries of the Harry Potter books. Other good websites are MuggleNet and the Harry Potter Wikia.
The stories that are featured on the Harry Potter Fan Fiction website are written by fans of the books or films of Harry Potter. They are written as if the author is in the Harry Potter story. Some of those stories are Never Alone, Days of War and Stolen Freedom.
They have a few, Harry potter spells, lego harry potter years 1-5, lego harry potter year 7 part 1, lego harry potter year seven part 2, and a lot of ones with posters, video clips and stuffs.