The DS18B20 has 3 pins, looking at it from the front (with the identification marks), the pins are Ground, Data and Power (3.3V).
You also need to connect a 4K7 resistor between data and Power. Have a quick google for DS18B20 and arduino, there are lots of example images showing the basic connection.
In my code, the data pin is connected to PA_5 which is pin 18 on the mDot and D13 on the dev board.
Regards
Andrew