We're working on a 2D Toolkit specific tutorial, but for now, you will find the Unity 3d platformer tutorial in Unity really relevant - you can easily replace all of the 3D assets with 2D Toolkit sprites and end up with a 2D platform game.
If you're getting started, the most important thing is to understand how Unity works, so any general Unity gameplay related tutorials will be really directly relevant. If you're not into scripting, then you should get something like PlayMaker. The tutorials we are developing won't go into great detail on scripting, etc.