Hundreds of events are expected to take place across Scotland to mark the annual World Book Day.
The world's biggest book, Bhutan, is put on display
The world's biggest book, a photographic record of the Himalayas measuring 5ft 7in, will be on display at the National Library of Scotland.
Visitors to Edinburgh Zoo can also choose an animal to illustrate - and thousands of book tokens will be handed out to children to encourage reading.
World Book Day is the largest annual celebration of reading in the UK.
Now in its 11th year, it grew out of the Catalonian tradition of presenting a book to your loved one on St George's Day.