ENWorld publishing Guild series. Its a pdf available through their on-line store. If you already have a paypal account your in business. They can also do credit cards, etc...
They have one for Thieves Guilds. Another good book is Gary Gygax's Canting Crew, available through Troll Lord Games and probably Amazon.
There are other resources but my old brain is blanking on them right now.
Song & Silence has some stuff in it for creating a Thieves Guild. It's 3.0 but I don't think it should make much difference. And you might be able to get it cheap too!
Michael Crichton's novel The Great Train Robbery is written all about a the great, Victorian-era train robbery, based on the original trial testimony. It's a wonderful read, and is especially useful for games like Victoriana, Age of Empire, or Cthulhu by Gaslight set in the 1850s-1890s.
From an in-game POV, while there have been several good supplements and articles on thieves guilds over the years, one that I have often returned to re-using is Ed Greenwood's "Assassin's Run" adventure/dungeon in Dragon 64. Quite good stuff, and well-worth looking up if you own the Dragon Archive.
Den Of Thieves - Its a 2EAD&D book, but the information about guild creation and chain of command is phenominal! I HIGHLY recommend it. Edition doesn't really matter since it all comes down to the people in the organization and anyone can roll-up/create NPCs.