Lytha.com  
   Large sections dedicated to the Thief series of games; including FAQ, newbie hints, surveys, detailled walkthroughs, loot lists and much more about the Thief series.
   http://www.lytha.com/

The Circle of Stone and Shadow  
   TTLG produced site which includes news, fiction, utilities and a large archive of fan-missions.
   http://www.thief-thecircle.com/

Thief Underground  
   Features articles, media, fan missions, tutorials and dromed resources.
   http://www.3dap.com/thief/

Zaccheus - The Honest Thief  
   Fan missions, links, tips and challenges. Includes dromed advice.
   http://www.rcl-software.org.uk/thief/

The Keep of Metal and Gold  
   A collection of fan missions with screen shots.
   http://www.keepofmetalandgold.com/

Garrett's Notebook  
   Includes a walkthrough which reveals the placement of secrets and loot hidden in the Thief 1 and 2 missions.
   http://www.3dactionplanet.com/thief/walk

The Keeper Library  
   Background details, hints and tips about the campaign world.
   http://www.btinternet.com/~sneaksiethiefsie/

Thief: The Dark Site  
   Comprehensive site dedicated The Dark Project. Guides to loot, maps, background and tips.
   http://thief-thedarksite.8m.com/

Adrenaline Vault Review  
   Screenshots and opinions, with details of the 'hidden' blooper level.
   http://www.avault.com/reviews/review_temp.asp?game=thiefg