From the home screen, select the blue 'New' button on the bottom right of the screen.
This will take you to the options screen, select the top option 'Record'
This will take you to the recording screen, press the centre green button to start recording your route. the blue arrows are the mileage and time elapsed.
The screen will go back to the maps, with an additional blue circle in the bottom right of the screen that shows that you are recording a route and the time elapsed.
To return to the recording screen press the blue circle. To pause the route press the center button, to stop the recording press the square button on the left.
It's also advisable to disable the auto record function, which can be found in setting - track - auto record just un-click it.