There is a very nice diagram about 3/4 way down the $40 robot page you linked to that show how the transistor and pots get connected.
Did you see this diagram?
What about it do you not understand?
In the diagram the Collectors do not connect to the pots, The Bases connect to the pots (blue lines).
The collectors connect to the +9V (red lines) and the Emitters connect to 1k Ohm resistors (black lines).