Good info (and entertainment) by others.
Some important basics...
First, I think it is a better sequence to send email before the call and let them know you will be following up... ask if there is a good day/time to reach them. Then, in both the email and the phone call...
Make sure you identify the right target... RC or HC. With the email, if in doubt, send to HC and copy RC.
Be positive and speak clearly. Nervous is perfectly OK. In fact, tell the coach you're nervous because it is important to you and you realize you only get one chance to find the best school.
Take the time to have specifics about what you like about the school and why you want to go there. Know some things about the program and what appeals to you.
Provide short bullet point highlights of why you are the type of player that can help him win. This, after all, is the primary reason he will be interested. Played successfully in the same scout league as his players, was first team all-state, 89 from the bump as a LHP with good secondary stuff, PG rating of 9, 6.7 60, etc. Be careful with game stats. They can be a plus with proper context. "I hit .380 in HS" means nothing. "I hit .380 in HS and was team offensive MVP in the biggest classification in state X" means something.
Provide concrete evidence that you are an upstanding student and citizen that will be a positive addition to the program.
Offer up credible references, preferably ones he might know or can easily contact.
Offer to forward a short video, assuming he hasn't seen you play. Of course, this means you have to have a good one ready to send.
If possible, try to find common ground... you went to a camp there, one of your classmates plays there, your dad went to the same college he went to, your travel coach told you what a great school it is, etc. Ice breakers, conversation starters, who-ya-know's are all good.