Setting up a basic gun

Ok, I want to set up a character that can attack with a gun. What would be a simple way to shoot with this gun and how would i simply do this via code?

Thanks~

Here are some scripts I found, it will even let you have multiple guns. Attach player weapons to your characters gun selector(create a game object). Create an empty GameObject. Place it infront of your gun, make it a child of your gun then attach Launcher to your empty object.Assign all of the variables, then you have your gun.

player weapons
function Start () {
// Select the first weapon
SelectWeapon(0);
}

function Update () {
	// Did the user press fire?
	if (Input.GetButton ("Fire1"))
		BroadcastMessage("Fire");
	
	if (Input.GetKeyDown("1")) {
		SelectWeapon(0);
	}	
	else if (Input.GetKeyDown("2")) {
		SelectWeapon(1);
	}	
}

function SelectWeapon (index : int) {
	for (var i=0;i<transform.childCount;i++)	{
		// Activate the selected weapon
		if (i == index)
			transform.GetChild(i).gameObject.SetActiveRecursively(true);
		// Deactivate all other weapons
		else
			transform.GetChild(i).gameObject.SetActiveRecursively(false);
	}
}

launcher

var projectile : Rigidbody;
var initialSpeed = 20.0;
var reloadTime = 0.5;
var ammoCount = 20;
private var lastShot = -10.0;

function Fire () {
	// Did the time exceed the reload time?
	if (Time.time > reloadTime + lastShot && ammoCount > 0) {
		// create a new projectile, use the same position and rotation as the Launcher.
		var instantiatedProjectile : Rigidbody = Instantiate (projectile, transform.position, transform.rotation);
			
		// Give it an initial forward velocity. The direction is along the z-axis of the missile launcher's transform.
		instantiatedProjectile.velocity = transform.TransformDirection(Vector3 (0, 0, initialSpeed));

		// Ignore collisions between the missile and the character controller
		Physics.IgnoreCollision(instantiatedProjectile.collider, transform.root.collider);
		
		lastShot = Time.time;
		ammoCount--;
	}
}

There is an FPS tutorial for free in the asset store if that is what you are trying to create