Coach and Advisor
The IHSA requires a team to have an official contact with the college (the advisor), and a person responsible for paperwork, forms, entries, correspondence, etc. (the coach).
The Advisor
The advisor must be someone in an official capacity at the college -- faculty, staff, administration. He or she may or may not be actively involved with the team but will be ultimately responsible for the team as its liaison to the college. If you have an established riding program at your college, it will be easy to find an advisor and coach in that department. If not you can usually find a faculty person in agriculture, animal science, or physical education that has some riding background and will be interested in your idea. However, your faculty advisor can be from any department on campus.
The Coach
Many teams have the luxury of riding at a campus facility with a college appointed coach. But a good number of teams will approach a local stable and make arrangements for a discounted group lesson rate with a local professional trainer or instructor. It takes a bit more organization and a good relationship with the stable, but you might be surprised to learn what a high percentage of teams operate in just this way.
The coach is usually a professional trainer or instructor who is contracted to work with the team, but is often the same person as the faculty advisor, especially if you have a riding program or agriculture department at your school. The contract may be oral or written, for whatever length the team feels comfortable -- usually a renewable one-year contract. But it is important to have the entire team training together with a common coach -- especially if the coach is traveling to shows with the team. The IHSA will only recognize one official coach (or one english and one western), and this has caused some substantial conflicts in the past for teams who allowed their riders to train wherever they wanted.
It is sometimes impossible to have a common coach for whatever reason, and the IHSA will allow a student to act in the capacity of coach, accepting correspondence, attending coach's meetings, appointing team point riders, etc. However, a student coach may not sign forms as the coach -- in such a case the faculty advisor should sign forms as the coach. However, it should be noted that some regions require every team to have a professional coach who travels to all horse shows.
The faculty advisor and coach may be the same person; in fact, this simplifies matters considerably. However, the IHSA strongly recommends that whoever signs the "liability waiver" forms for each rider and for each horse show entry (the coach) should be familiar with the riders and their abilities, enough to attest to their safety and suitability. The coach, in signing those liability forms, is opening himself/herself up to future litigation should a rider be in over his head and get hurt. Therefore it is important the coach be familiar and comfortable with all riders on the team, which is why most teams have mandatory practice sessions with their coach at least once weekly during the show season. Also, riders who will compete over fences are required to have had at least six months continuous professional training over fences.
It should be noted that some regions have regional policies that require professional adult coaches. Check with your Regional President. Either way, it is highly recommended to have a professional adult coach.