where can i get  information on errors?

#include <AFMotor.h>

AF_Stepper motor(48, 2);

void setup() {
Serial.begin(9600); // set up Serial library at 9600 bps
Serial.println("Stepper test!");

motor.setSpeed(10); // 10 rpm

motor.step(100, FORWARD, SINGLE);
motor.release();
delay(1000);
}

void loop() {
motor.step(100, FORWARD, SINGLE);
motor.step(100, BACKWARD, SINGLE);

motor.step(100, FORWARD, DOUBLE);
motor.step(100, BACKWARD, DOUBLE);

motor.step(100, FORWARD, INTERLEAVE);
motor.step(100, BACKWARD, INTERLEAVE);

motor.step(100, FORWARD, MICROSTEP);
motor.step(100, BACKWARD, MICROSTEP);
}