Today marks World Book Day, an annual event designed to encourage parents to read to their children.

As well as hundreds of reading events taking place around the world, many schools have also been marking the event by encouraging pupils to dress up as their favourite characters from literature, with Harry Potter and the Gruffalo being among the most popular costumes.

To celebrate, here below we list ten of the best book-related world records.

Youngest person to write a published book
The youngest commercially published female author is Dorothy Straight (b. 25 May 1958), of Washington, DC, USA, who wroteHow the World Began in 1962, aged 4. It was published in August 1964 by Pantheon Books.

First free-standing bookcase
The first free-standing bookcases were built for the noted diarist Samuel Pepys (UK) in 1666, and one is currently on display at the Victoria and Albert Museum in London, UK. Pepys, who commissioned the bookcase, had asked his joiner to build him a set of free-standing bookcases with protective glass doors while instructing his bookbinder to gild the spines of his books " make them handsome".

Largest book signing
The most books signed by one author in a single session is 4,649 by Sammy Lee (Hong Kong) who signed "Autopilot Leadership Model " by Sammy Lee in Shenyang, Liaoning, China on 19 January 2013.

Highest earning adult fiction author
In terms of book sales and earnings, James Patterson (USA) is the most successful author of adult fiction. He has sold more than 200 million books since 1992 and in the 12 months to 1 June 2010 alone earned $70 million (£46.5 million).

Fastest selling book of fiction in 24 hours
The fastest selling book in history is Harry Potter and the Deathly Hallows, the seventh - and final - novel in JK Rowling's (UK) Harry Potter series, which sold 8.3 million copies in the first 24 hours (or 345,833 books per hour), following its release in the USA at 00.01 on 21 July 2007.

Rowling also holds the record for Highest annual earnings for a children's author having notched up an estimated US$300 million (£150 million) between in 2007-2008 according to the Forbes Celebrity 100 list released on 11 June 2008.

Largest collection of books owned privately
John Q. Benham of Avoca, Indiana, USA has a private collection of over 1.5 million books.

As they have filled up his house, most of them must be kept in his six-car garage, two-storey building and piled under tarpaulin outdoors.

Longest marathon reading aloud
The longest marathon reading aloud is 113 hours 15 minutes achieved by Deepak Sharma Bajagain (Nepal) at the Tudikhel Ground, Kathmandu, Nepal, from 19 to 24 September 2008.

He recited 17 different books from 13 authors during his record attempt.

Most abandoned book
The most abandoned book is Simon Cowell: The Unauthorised Biography by Chas Newkey-Burden.

A 2010 survey of thousands of books left behind by guests at 452 Travelodges in Britain revealed that the X Factor star's biography topped the list.

Highest library
The world's highest library is located on the 60th floor of the JW Marriott Hotel at Tomorrow Square in Shanghai, China, at 230.9 m (757 ft 6 in) above street level.

Membership is available to the public, and the 103 shelves in the library contain an ever-expanding collection of Chinese and English books.

Best-selling copyright book
And finally, a record of our own that we're all very proud of at Guinness World Records HQ.

Excluding non-copyright works such as the Bible (with an estimated 6 billion copies sold) and the Koran, the world's all-time best-selling book is Guinness World Records (formerly The Guinness Book of Records).

Since it was first published in October 1955, global sales in some 37 languages have exceeded 124 million as of October 2010.