There are currently four tutorials listed here.
Movement Skills Tutorial - covering all the ways to move and groove in the Thief world.
The Staircasing Tutorial - how to create a floating staircase of crates. A very useful guide on making a stack of crates of any height using far fewer crates than the traditional Stack 'Em Up method.
Flare Elevatoring Tutorial - the most advanced and flexible climbing method yet discovered. climb up, down and sideways with ease.
Keyholing Tutorial - how to pick up and manipulate objects that are hidden behind locked doors.