How to put the diodes in order to protect the Arduino?

Can you please tell me how to put the diodes in order to protect the Arduino from a Dc Motor, I am using the driver L298 and the Arduino mini pro

In this project I need to drive also an stepper motor, Do I need to put diodes to the stepper too?

I am using the diode 1n4007, it has a white band on it, in what direction should that band go


Refer to the L298 data sheet for how to configure the diodes. Figure 6 is for bidirectional DC motor control. Figure 8 is for bipolar stepper motors.

I don’t understand the figure, can you please explain me

I know that the diode is the figure with the arrow shape, but the frontal face of the arrow is the white band of the diode? or backwards?

The schematic representation of a diode is an arrow pointing to a bar. The arrow is the direction of current flow.
The white band (can also be a black band) on a diode is the bar end.