from what I gather the propeller (simplified) uses the same principles as the wing. As it rotates it is presented to the airflow at a certain angle of attack and the airflow over the top (front of the prop) is faster creating a lower static pressure therefore creating lift (thrust) so in escence sucking the aircraft forward. As long as the force is not less than drag then you will move forward. If the "lift" (thrust) created by the propeller is greater than the drag you will accelerate until the lift (thrust) is equal to the drag and then you will maintain speed.
Am I on the right Lines??