There are four phases to every freestyle arm stroke.  They are catch, rotation, follow through, and recovery.  This lesson explains how to increase your surface area for more propulsion.  Think of grabbing a water ski rope suspended 12" under you.  Now think of taking longer strokes that will allow you more time to exhale and inhale 10-20% of your air supply with each breath so you can swim continuously without stopping.

When you are more streamlined and efficient you'll take one right and one left arm stroke and should travel the length of your body.  This conserves your air supply so you don't have to stop to take a breath.  Swimming needs to be like a walk in the park.

In swimming you float first and swim second.  Let the water buoy you up by keeping air in your lungs rather than try to fight through the water.  Water weighs 62.5 lbs. per cubic foot.  You can't win unless you know how to float really well to go with the flow.