Farseer Physics and Character Control

Hello, I've been trying out FarseerUnity for some time, and came up with a problem. I want to create a box which is controlled by the keyboard - that can go left and right, and, of course, jump. I have never really used Farseer Physics or Box2d before, especially with Unity. So, I need a place to start.

Also, I've seen this done in XNA by adding a circle to the character with a motor attached. Is there a more efficient way to do this in Unity?

Any help is appreciated.

Thanks. (If you have code, I would prefer C#. If you can, of course)