Some basic information:
Discworld is based on the series by Terry Pratchett. It is, by and large,
a comedic fantasy setting. However, the easiest way to make a character
is to pick a general fantasy character and then make a slight
twist. Straight characters are fine too - funny stuff will happen
regardless of the character. If it helps, making a Typical Archetype such
as one might see in D&D would work. No knowledge of the actual books is
necessary, though if you want to read any I have them all.
General storyline: This will be a Quest type thing, where you wander all over the Disc. We will start in Ankh-Morpork. If you want to know other characters at the outset that will make things easier, if not that's fine too.
You may NOT play any of the known characters from the books (unless perhaps they are an extremely minor character)
Things your characters must have:
Dwarfs
Disc dwarfs average about four feet in height. Both genders have beards and have an average life-span of around 300. Puberty is around 56. They also wear a great many layers of clothing, making gender recognition difficult. There, until recently, was no dwarf equivalent of the word 'she'. This leads to interesting courtships, as at some point some subtlety must be used to determine the sex of the other dwarf...
Generally a subterranean species, they have very keen sense of depth underground and night vision. They are miners by nature. Their culture revolves around it, especially gold mining. Almost all dwarf songs are about gold, the most famed being 'Gold, gold, gold'. It has been said that dwarfs love gold. Many dwarfs claim this is not true; they just say that to get it into bed. A further note should be made of dwarfish literalness. They do not use and have trouble understanding metaphor and simile. Rocks are hard as rocks, darkness is dark. To start getting poetic when you live in a mine would be dangerous.
Dwarfs have an ancient racial feud with trolls. The reason for it has been long lost in the murk of history, and now for a dwarf, the only reason needed is that they are trolls. Of course, dwarfs being miners, dig things out of rock. Trolls ARE rock. So this could well have been the start of it all. The most famous battle is was the Battle of Koom Valley, the only battle known in which both sides ambushed each other. "Remember Koom Valley!" is a battle cry known on both sides.
A great many dwarfs have moved to Ankh-Morpork, making up the largest non-human group. Although dwarfs are usually quite serious and hard working, they have a tendency, upon reaching the city, of drinking and then attempting to remove limbs and any other protrusion with axes.
Trolls
Trolls are your basic silicon based life form. They are humanoid, but on a large scale. Trolls never die, although they can be destroyed. That is to say they do not die of age. However over the years a troll may grow increasingly large, and settle down to think. Slowly, perhaps over thousands of years, they cease to think and become geography.
Being silicon based life forms, trolls are effected by heat. In cold climates, they are intelligent, even cunning. In the plains however, the heat reduces most of them to imbeciles, the rest to just annoyingly stupid.
Trolls are not subtle. Their language mainly consists of body language. They eat rock, they're usually named after rock, they are rock. On arriving in the city, most trolls end up drifting from one job to another, as each employer finds it too expensive to keep them on. The three major exceptions in Ankh-Morpork are Detritus (works for the Watch), Igneous (runs a pottery shop and does illegal drugs on the side) and Chrysoprase. Chrysoprase is a nasty exception, having picked up a lot of characteristics form humans. He is Ankh-Morpork's premiere crime boss.
Other Races
There are a number of other races in Ankh-Morpork and beyond. This only touches on a few for character creation.
Gnomes are very small creatures, somewhere around 6 inches high. They are very fast and very strong, having the strength of a normal man but concentrated into a much smaller area. The most well-known gnome in Ankh-Morpork is Wee Mad Arthur, a non-guild ratcatcher (who doesn't have any trouble staying non-guild, despite the Guild of Ratchatcher's best efforts).
Zombies are yes, those people who have died but refused to move on. In fact, zombies are those people who decided to get on with their life, usually taking it all with them as they did. A zombie can be from pretty much any walk of life, although a good reason why they became a zombie rather than just dying like normal people is required. Disadvantages are their flesh tends to rot off eventually, though they do tend to have lots of strength.
Werewolves are for the most part like the werewolves of legend. There are some differences though - werewolves can change at will and don't need there to be a full moon. However, during the full moon a werewolve must change if moonlight hits him/her. It is possible to control the werewolve instincts (particularly of treating people as food) but it becomes much harder near the full moon. Immediately after a Change, the werewolf retains enhanced senses of whichever part it just changed from.
Golems are nearly indestructible. There are very few of them, and those that exist (except Dorfl) require a master. They have words in their head which give them rules about what they cannot do (Thou Shalt Not Kill, etc). Golems do not have the ability to speak, but carry a slate and chalk to write what they want to say. Most golems are hundreds of years old.
Bogeymen tend to hide behind something or lurk in shadows. Their primary function in life is to scare children. One way to combat them is to cover them with a blanket. As children hide under blankets to hide from Bogeys, knowing that they can't get them there, this forces the bogeyperson in question into a state of existential uncertainty that takes a while to wear off.
Tooth Fairies** and other random fantasy characters from fairy tales generally exist on the Disc. The most famous is perhaps the Tooth Fairy franchise. If you want to play something like this, let me know and we can work out details.
Barbarian Heroes***
Thieves
Assassins
Random Persons from Ankh-Morpork
Etc.
* usually not very pleasant ones
**This is also an Occupation
*** or just someone with the book "In Juste Seven Days, I Wille Make You a
Barbarian Heroe"