Discworld can appear quite strange to a new visitor, so this guide is intended to give valuable information about the places you will see, and the people you may meet.
Across the endless gulf of space, a giant turtle swims. On its back, supported by four elephants is the Discworld. Discworld is unlike most worlds, in that it is flat. The reason ships appear to fall of the edge of the horizon is that they do fall off the edge of the horizon. Around the edge of Discworld is the rimfall, where the oceans pour away into space. For the record, the turtle is called Great A'Tuin, and the four elephants are Berlia, Tubul, Great T'Phon and Jerakeen. The sex of Great A'Tuin is still unknown.
Discworld is not entirely unlike J.R.R. Tolkein's Middle Earth, in that is is inhabited by gnomes, trolls, wizards, witches, elves, goblins and other, more improbable, characters. Mechanism has spread only as far as the horse and cart, and Discworld is, in many ways, a lot less complicated than the world which we inhabit, although there are many parallels between their world and ours.
Magic plays an important part on the Discworld. Magic in it's raw form is a force, not unlike gravity, or electricity, in that it cannot be seen by ordinary men, only its effects can be observed, be they making a pigeon appear, or something more elaborate. Magic does, however, have a colour, octarine, produced by sunlight falling on a magical field. Wizards are able to see octarine, and they describe it as a kind of fluorescent yellowish-greenish-purple. Wizards are, of course, the chief exponent of magic, although it is also practiced by some of the Disc's Witch population.
The Unseen University is the main seat of learning magic on the disc. All Wizards study there for the degree DM (Unseen), although only one spell need be known to graduate. The books of magic are stored in the Library at the Unseen University, and are overseen by the Librarian, who is an orang-utang (Not a monkey). In fact he used to be a Wizard who was transformed into a orang-utang, by a magical accident, and he resisted all attempts to turn him back, as he found the long arms useful.
In Equal Rites, the disc gets its first female Wizard.
Ankh Morpork is the largest city on the disc; a hotbead of corruption, violence, and general underworld lowlife. The city is supposedly policed by the City Watch, but in effect, a system of licenced criminals mean they are unnecessary. The main criminal groups - thieves, assasins, etc. - are represented by official guilds and, for example, the Guild of Thieves are allocated an amount of money each year which they can legally steal from the public, and in this way, any unofficial thievery is discouraged by the Guild in no uncertain terms. It is this that makes the City Watch, the natural defender of law and order, pretty much pointless.
The Shades is the gloomiest, most dangerous area in Ankh Morpork, where lawlessness does rule, and even the Watch do not enter if at all possible. Any one who wanders in by accident generally doesn't stay there for very long...
One of the most popular ale houses in Ankh Morpork is The Mended Drum. It used to be called The Broken Drum but it was burned to the ground in the Disc's first insurance scam. (See The Colour of Magic)
The city od Ankh Morpork is governed by the Patrician.
Death is the only character to appear in all the Discworld novels. As a traditional anthropomorphic personification of the afterlife, he is a skeleton, dressed in a robe woven from pure darkness, and carrying a scythe so sharp, it is transparent. Death is in fact not scary, just very good at his job. He tries hard to understand humans, but prefers cats.
Death can only be seen by animals, some children and Wizards. Of course after the point of death, he can be seen by the deceased, at which point he cuts off their lifeline with the scythe, and escorts them to their afterlife. Death is occasionally accompanied by the Death of Rats (aka The Grim Squeaker) who takes care of the final need of rats, mice and other small animals.
Many other characters crop up repeatedly in the novels. Some people you may meet on your travels are:-
Rincewind is the Disc's worst wizard. Due to a complicated series of events, he can only remember one spell. However that still qualifies him to be a wizard, and to prove it he has a pointy hat with WIZZARD embroided on it. Rincewind spends most of his time trying to avoid doing anything remotely resembling work, and the rest of the time trying to get out of danger.
Although not strictly a character, the Luggage does feature in many of the novels. It is a large travelling trunk which sometimes has hundreds of little tiny legs with which it will follow its owner. The Luggage also occasionally has lots of sharp teeth beneath its lid to discourage non-rightful owners from exploring too deeply its contents. Twoflower the Tourist presented Rincewind with the Luggage as a gift at the end of The Light Fantastic.
"Granny" Weatherwax is a witch. However, contrary to popular opinion, Witches are not wicked, and as a rule don't do much magic. "Granny" knows that most of the time, being a witch is all about image, so she wears lots of layers of dark clothing, and a black pointy hat, and says a lot of mystical-sounding words that don't do anything. Her remedies for illnesses are more likely to contain natural herbs than anything occult. She also acts as a local midwife for her area.
Susan is Death's granddaughter. In fact she is Death's adopted granddaughter, as her mother, Ysabell, is Death's adopted daughter. (Her father is the eponymous hero of Mort) Although the family connection means that she can occasionally walk through walls, and speak in sentences of pure stone, she tries to control these actions and lead a normal life as a Nanny.
A member of the Ankh-Morpork City Watch, Carrot is a human, raised by dwarves, and only realised he was different when he grew to be six feet tall, so he left the dwarven community to seek his fortune in the watch. His name refers to his tapering body shape - when he flexes his muscles, people have to move out of the way first.
Hogswatch Night marks the beginning and the end of a disc year (which has eight seasons). Tradition has it that every Hogswatch Eve, the Hogfather creeps down the chimney of children's homes to dispense gifts, in return for the Sherry and Pork-Pies left out for him. Tradition does not record how he visits every child in one night, but it is known that he is fat and jolly, wears a red robe, and rides on a flying sleigh pulled by four pigs.