I've noticed many newbies who can't find their way around TCB. Here's a guide that will help them in what levels to go to, but it won't mention precisely how to get there.
×The High Path (technically before the Infohut)
Infohut
-------1st Gate-------
The City - 1st visit
The Naming Office - 1st visit
The City - 2nd Visit
The Fork - 1st visit
Quest for Knowledge - 1st Puzzle Level
The Fork - 2nd visit, blue door down
The Grand Library - 1st Visit
The Fork - 3rd Visit
The Uncturage - 2nd Puzzle Level
Deep Uncturage - 3rd Puzzle Level
The Uncurage - Journey back up
The Fork - 4th visit
The Grand Library - 2nd Visit
Under the Library - 4th Puzzle Level
Interlude: Negotiations - 5th Puzzle Level
The Grand Library - Return to the front desk
The Fork - 5th Visit
The City - 3rd Visit
Homeward Ascent - 6th Puzzle Level
Midway Outpost - 7th Puzzle Level
Echo Chasms - 8th Puzzle Level
The Villa - Bombus Gadhan's House
Dugandy - 1st Visit
King Dugan's Castle (Armaments)
Dugandy - 2nd Visit
King Dugan's New Dungeon - 9th Puzzle Level
King Dugan's Castle (Castle)
Dugandy - 3rd Visit
River Dugan - 10th Puzzle Level
Holding Vats - 11th Puzzle Level
Homeward Ascent - 2nd Visit
The City - 4th Visit
The Naming Office - 2nd Visit
Twenty-Fifth Level - Beethro's Dream
The Naming Office - Slayer Puzzle
The City - 5th Visit
-------2nd Gate-------
The City Puzzles (The City West Side)
The Patronage
DAA Headquarters
Archivist's Lobby - 1st Visit
Slayer's Convention - Slayer tells you what to do
Archivist's Lobby - 2nd Visit
Archival Catacombs - 13th Puzzle Level
Archivist's Lobby - 3rd Visit
The City - 6th Visit
Slayer's Convention
Torture Chambers - 14th Puzzle Level
Rooted Hub
Oremite Breeding Grounds - 15th Puzzle Level
Estengard - 1st Visit
Rasarus Archipelago - 16th Puzzle Level
Pirate Hideout - 17th Puzzle Level
Rasarus Archipelago - 2nd Visit
Estengard - 2nd Visit
Oremite Breeding Grounds - 2nd Visit
Rooted Hub - 2nd Visit
The City - 7th Visit
-------3rd Gate-------
The Asking Chambers
The City - 8th Visit
Click here to view the secret text
×Infohut - 2nd Visit
Stalwart Preparation
Stalwart Battle - 1st Visit
Interlude: A Goblin's Eye View - 18th Puzzle Level
Stalwart Battle - 2nd Visit
Forgotten Ruins - 19th Puzzle Level
Frozen Depths - 20th Puzzle Level
Rocky Hollow - 21st Puzzle Level
Abyssal Fortress - 22nd Puzzle Level
Upper Lowest - 23rd Puzzle Level
Lowest Proper - 24th Puzzle Level
Click here to view the secret text
×Lowest Point - Ending
Click here to view the secret text
×The Undercity - Uber-secret Legendary Mastery Level
Well, that's my list. I know I haven't included some of the levels at the end, but that's only because I haven't gotten that far yet. Please update this list.