If you have asked the court clerk to serve your papers by certified mail, you need do nothing else. The court clerk sends out the certified mail for you, and the signed post office receipt comes back directly to the clerk if service is accomplished. It's as simple as that.
However, a court has no way of knowing whether or not papers have been successfully filed by personal service, substituted service, or first-class mail unless you tell them. So, you are required to do so. Notification is accomplished by filing a form known as a Proof of Service with the court clerk after the service has been made. (See "Sample Proof of Service," below.) The Proof of Service form must be signed by the person actually making the service. A Proof of Service is used both by the plaintiff and by the defendant if the defendant files a defendant's claim. It must be returned to the clerk's office.