Mouse movement and click effect

First off I appreciate any help. I am a complete newbie to this. I am attempting to create a game and I need help. I have an object that I want to control with my mouse movements, how do I accomplish this? Also, I want to make it so the initial mouse click, and initial mouse click only, activates a ball to move in one direction.

Again I appreciate any help. Thanks :)

 function Update ()
 {
 var horizontalSpeed = Input.GetAxis("Mouse X");

 var verticalSpeed = Input.GetAxis("Mouse Y");

 transform.Translate(Vector3(horizontalSpeed ,0 ,verticalSpeed));
 } 

This will rotate your ball using your mouse. Please tell me if this gives you any errors if so I will look at it tomorrow :)