Invitations should be sent to all parents and athletes who are invited to the banquet.  If mailing invitations, the athletic department can assist you with providing mailing labels.  Invitations vary from something that looks like a wedding invitation to a simple on-line “Evite.”  Make sure that when you request an RSVP that the name of the athlete and number of guests is noted.  Evites often go to the athlete and parents separately and then you need a way ensure you do not have duplicate responses.  It is also nice to provide a list of attendees to the coach.