J. K. Rowling
This is the official J. K. Rowling website.

The Harry Potter Lexicon
This is one of the best HP sites out there for information.  Just about  anything you want to find, you can find here.

Official Harry Potter Website
This is the Warner Brothers official Harry Potter website.  There's a Sorting Hat test somewhere on here, and a wand-picker, not a bad resource for choosing houses and wands for original characters.

Freesearch UK Dictionary
This is a UK based dictionary.  It's been invaluable to me in finding out what some English terms (like "skip", which is their word for a Dumpster) mean.  You can also look up words here and it will tell you if it's a US or UK based word.  Such as "pancake".  A pancake in England doesn't seen to be the same as in the US.

A Dictionary of Slang
Here is a good site for British slang.  It has dozens of words, and even the area where each word is usually used.

British Slang Words
Here is another British slang site, a rather shorter, alphabetical list.

British Dialect Translator
I don't know how accurate this one is, but it's a lot of fun and can offer some insight as to how some dialects might look in type.

Metric Converter
This website converts inches to centimeters, Fahrenheight to Celcius, and several other units of measurement.

Magic Properties of Wood
This is a cool site which tells of the various magical properties of wood, according to Wiccan tradition.

Alivan's Makers of Fine Handcrafted Magic Wands
This is a commercial site, but looking at the various wand descriptions is a fun way of choosing a character's wand. 

United Kingdom on Wikipedia
Here's a whole lot of information on the United Kingdom.

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