Arduino and controling an eight wire stepper

Hi guys,
I bought teensy board for my project . You can run arduino code on it. I got a bipolar stepper motor (55M048D2U).

now, about coding im confused. How can we decide if it rotates clock wise or counter clock wise? i mean are we reading 2 different signal? im very very confused

A stepper motor steps. Hence, the name.

If the steps are performed in one order (A, B, C, D, ...), the motor will rotate one way. If the steps are performed in the opposite order (..., D, C, B, A) the motor will rotate the other way.

Typically, a motor driver board will take care of making sure that the motor steps in the forward or reverse directions for you.

Driving all but the tiniest stepper motors directly from the Arduino (or Teensy) is not advised.

The direction depends on how the coils are wired and what sequence they are switched. See:-
http://www.thebox.myzen.co.uk/Workshop/Motors_3.html

and
http://www.thebox.myzen.co.uk/Workshop/Motors_4.html