1. An object, not affected by a force, will continue doing whatever it was doing.  For example, a stationary object will remain stationary until acted upon by a force.
2. When a force acts on an object, the object is accelerated.  (F=ma)  For example, a stationary object acted upon by a force will accelerate in the same direction as the force.
3. If you push or pull an object, it pushes or pulls against you with the same force.  For every action there is an equal and opposite reaction.

It is important to note that these three laws are not exactly right, they are approximations to what we believe the laws of motion are today.  However; these three laws of motion have been very useful in the "world of direct observation."  These are the laws that engineers use to build houses and cars and things.  It is not until you look at things that are very small (quantum mechanics) or very big (cosmology) that we find errors in Newton's laws of motion.

Some people believe that Newton was the most important scientist of all time because he discovered that objects move in accordance with some very simple mathematical expressions.

(rav)