My instructional approach:

I am of the firm belief that the first skill each child needs to
master is how to be “safe” in the water. Regardless of how
good a swimmer you are, if you can’t “rest” in the water by
getting air and laying still, you will quickly become tired. This
is why the first thing I teach children is how to float on their
back. Teaching a child to float first, ensures increased
confidence in the pool and allows the child to realize that in
spite of any other circumstances (water depth, sudden
fatigue, a body cramp etc.)
he or she knows that they are
able to save themselves at any cost

After your child can float, we progressively learn to swim one
step at a time.  My goal is to have your child swimming the
length of the pool by the end of the eight lessons; however I
will admit that this does widely depend on your child’s agility,
coordination, and acclamation to the water. Although some
of these factors are a mere matter of maturity and
sometimes just come with age, it does help tremendously if
your child feels comfortable around the pool and has been
exposed to the water a number of times before lessons
begin. I have often found that the children that do best in
lessons are the ones that come mid-summer or towards the
end for this very reason.
How can you help your child be ready for swimming lessons?
By encouraging them to put their “whole” face in the water (this includes
their forehead, nose, chin, and cheeks all the way up to their ears
) and
teaching them to “blow bubbles” out their nose in the water. This is a
prerequisite for private lessons and these skills can be practiced in your
bathtub at home (without bubble bath of course).