1. They should only call a program/coach, in which they are sincerely interested in. Further, if they are a Freshman, they should not call at all. If they are a Junior, then they should only call the coaches who have been consistent in sending emails; it is lazy of the coach to send one email and then say 'call me' - I think the coach has to do their job and 'recruit' by developing a rapport over the emails first. The sophomore year is a bit tricky because of communication rules.
2. The first call should be an established time; this can be done via email. Even the sophomores can write and say, I will call you tuesday at 9 p.m. The juniors can easily email and determine a good time to call.
3. The first call should also be a family call - It should be on speaker phone with the Dad/Mom also on the call. I suggest the parent start talking first; make the call, say hello, chit chat a bit and then 'hand it' over to the player. This will provide some comfort for the player, and keep the parents involved in the recruiting communication.
4. Have a short list of questions; How is the spring training going for your team? What does the team usually do in the off season for volleyball? Have you determined what spring tournaments you will play in? Give them a quick update on how the club season is going? Let them know when the next trip to the mainland will occur.
5. I would not dive too deep into the academics/program philosophies/meaning of life on that first call. It is more just a soft touch, meet and greet, chit chat to get a feel for the coach and how they communicated. On the second call, or unofficial visit, that is when you want to get serious about the serious stuff.
Hopefully this gives a starting point in the verbal communication part of the recruiting process.