The website below is fairly good for Harry Potter information:
http://www.mugglenet.com/
(If you've got another website, please add it).
I used to visit www.hp-lexicon.org, but more recently, I get most of my information from en.wikipedia.org.
A Google search will show up quite a few. Specific sites include the Wikipedia, which has several detailed articles about Harry Potter, and the Harry Potter Lexicon.
Some good sites for Harry Potter news and entertainment are fansites like Mugglenet and Leaky Cauldron. The best site overall for Harry Potter is Pottermore, an official Harry Potter experience. It opens to all in October.
mugglenet.com is an excellent one.
http://tinyurl.com/nxrn2q
The Leaky Cauldron is a good site and IMDB have some as well
The Leaky Cauldron, MuggleNet, and Harry Potter Lexicon are my favorites. See the related links below. i go to Potterforums.com i am a member there so you can ask me anything about it
There is nobody with that name in Harry Potter.
A copy of the book Harry Potter and the Goblet of Fire can be purchased from all good book stores. Try Waterstones, Walmart or sites such as Amazon or Ebay.
Answers.com has summaries of the Harry Potter books. Other good websites are MuggleNet and the Harry Potter Wikia.
Harry Potter and the Half-Blood Prince was FANTASTIC!
There probably won't be anymore, unless JK Rowling releases the Encyclopedia of Harry Potter which is speculated to possibly happen, but check out her website, there's quite a lot of extra information and she's released stuff on other sites as well about the kids, and the jobs and some things she has decided would happen. Good luck!