These are some of the sites, created by Discworld players. You can find more complete, but uncathegorised list here

Geography

Discworld is big. It has over gazillion unique locations! When you need to find wehere the Sek you are now or WTS is that street/city/continent you need to get to, maps, created by players, are your best friends.

Most well-known maps page is Airk's atlas. It has maps of about everything, except wilderness. Bad thing is that he got WoWed lately, and don't update maps anymore. If you want more (likely, most) up-to-date versions of that maps, visit Kefka's site. Only drawback of Kefka's site is that it seems to be offline occasionally, so you may prefer to download his maps, just in case.

As about wilderness, Boots maps are unrivaled. He has very precise maps, containing about every square mile of in-game parts of disc (and man, there are lots of them). He has cities maps as well, not as up-to-date as Kefka's, but a little more informative and thorough.

Other maps of terrains can be found on Peta's page. They are not as thorough as Boots, and not as insanely huge.

If you need maps of some more obscure places, like Genua sewers, Grflx caves etc, try Zuroc's maps. There are lots of interesting maps there, and only drawback is that this site uses jscript aggressively, which can be buggy on some browsers.

You can find another interesting map page on Thieves guild page. They are old, and not very user-friendly, but has very interesting pieces, like precise-to-location map of SUR terrains, or map od Bes Pelagric complete with black market

ZMud

It's great to see the map, but it is also great to show map to computer and ask it to do some dumb things, like, walking you to specified location, while you relax in you chair and think WTS you are going to do, when you'll finaly got there.

For that, you can use ZMud and fine ZMud-compatible maps, created by fluffy players.

My favorite ZMud map is Oozenthor's Cmud / Zmud Map Most up-to-date and have a lots of rooms, including roads and terrains near cities (so you can speedwalk from Sto Lat to AM!)

Other ZMUD maps are Fewyn'sRal's and Regina's.

Numberchasing

If you one of those strange people that are fond of endless kill-stuff-to-get-expirience-to-levelup-to-be-able-to-kill-stuff-better cycle (or just want to know how to make you chareacter more effective in stuff), here are the sites that will help you in that.

Begin with Skills, Stats and Bonuses site. All basic info and some calculators to find, like, "How much xp I need to get bonus 400 in my favorite skill. And btw, what is this 'bonus' thing?"

Other popular site is Flatline's skill page Here you can submit your skills and see other's. Just to show off, or, mor importantly, to gind someone who can teach you some skill.

Guilds

If you want in-depth info about some specific guild, check these sites.

Assassins

Malicious' Assassin Site Up-to date information about nearly all you need to know about all branches of guild.

Wizards

The Spellcheck Project Very thorough site, including all the range of information from newbie advices to exact probability of failure of each skillcheck for each spell. And also nicknames of all spells (Yay! I know what is "eff" at last!)

Priests

Faces

For some reason, people want to see how each other looks. Like if text description is not enoigh. So, there are several sites about how players (or their cahracter) looks.

Photos of player.

Solace's Hall of Shame Big, classic, abandoned in 2005.

Words

Some words are worth to be carved if not in stone, but on web page, at least. Mostly just for laughs.