I've never heard of the Feminine or Masculine Principles, what do I need to know first? 

Here is the key point:  Everyone has both the masculine and feminine principles within them.

It is not the same as gender.

This is so hard to understand since we have been conditioned to gender differences all our lives.

In reality, every person is perpetually trying to balance our feminine/masculine “duality.”  We are always in the process of creating ourselves, our “wholeness,” whether we are conscious of it or not.

If people are too tilted to the feminine, they may have wonderful creative ideas that are never manifested since masculine energy is necessary to put this creative project out into the world.  If people are too tilted to the masculine, the idea may not be given time to be ready to share or be suppressed completely.  Together the two energies complete the creative process.

It is a continual, internal dynamic of the process of life.

Too much masculine energy within a person, group or society leads to destruction.

Too much feminine energy within a person, group or society leads to chaos.

Balance is necessary.

Our job is to become conscious of when we see the masculine or feminine principles operating within ourselves and the world.

Feminine and Masculine energies are balanced in all healthy manifestations--equal partners, lovers, the truest twin friends—even in organizations that are balanced in their leadership and policies.  Things have been out of balance for 2000 years or more.

Will I ever be in perfect balance?  No, life is a dance between the feminine and masculine energies and you may use more of one or the other at different times in life.

The Yin/Yang Symbol represents this duality with two complementary parts which are polar opposites.  Together they create a dynamic whole.

Here is a concrete example of the feminine principle:

Nancy works with horses and recently changes her training method to a more feminine energy one approach in contrast to a dominator model that she had previously used.  Now she first listens to the horse and then guides it in a mutually acceptable way (F), versus giving commands and leading the horse solely in the direction that you wanted it to go (M).  This mutual/reciprocal method produced results that were more satisfying to both horse and rider.