One of my favorite books, and one that I would strongly suggest all coaches read (regardless of sport) is “Finding the Winning Edge” by Bill Walsh. He goes into great detail about every phase of running an organization including what he thinks is involved in being a good assistant coach. Here is what he had to say:
Among the qualities that you, as the head coach, should look for in an assistant coach are the following:
A fundamental knowledge of the mechanics of his position.
An assistant coach must be technically competent. If you hire an assistant who does not have the technical knowledge necessary to do his job properly (a fact that will soon become apparent to the players he coaches), you may create an environment where the players will begin to question your competency as well.
Ability to communicate. An assistant coach must be able to communicate with the players in a relaxed, yet authoritative manner. Such a quality is the fundamental basis of an assistant’s ability to effectively teach and interact with his players-perhaps the two key responsibilities of every assistant coach. The assistant coach is the most direct link a player has with the game and learning how to play it well.
Ability to evaluate and project talent.
A relatively high level of energy.Assistant coaches must exhibit an appropriate level of energy that enables them to be upbeat, motivated, and animated while in the presence of the players and their fellow employees. It is not unusual that a group of players will collectively take on the personality of their position coach. If a team has an assistant coach who is a negative, complaining type who sees inadequacies in everything around him, the situation can be quite downbeat.
Loyalty. Assistant coaches must exhibit loyalty at all times, both to the head coach and to their fellow coaches. No offense should be viewed more seriously than disloyalty, especially among coaches who should know better. An assistant coach who feels compelled to criticize or demean a staff member to others in the organization, media, or fans can be an extraordinary disruptive force. Accordingly, the head coach must not tolerate disloyalty in any form.