Sighting in your rifle is an important process that needs to be performed every time you purchase a new firearm, scope or sights. This allows you to ensure accuracy and gain specific knowledge of your weapon needed to maximize effectiveness. How it kicks, what the drop is and how your body reacts to each round fired. Every firearm acts differently, even ones of the same make and model.
What you'll need;
[1+] Rifle (scope mounted)
[2+] Box of ammo
 Package of targets
 Milk crate
 Roll of tape
Ideally you'd want another person with you and you need a safe place to shoot.
Step 1: Firearm Safety
It is important to know basic firearm safety. First, the safety should remain locked until you are ready to fire. The action should remain open on the range until ready to fire. Always point the muzzle up, down or downrange unless there is someone downrange. In the case of someone walking downrange, it should be announced by the person walking into the line of fire. Never point the weapon downrange while someone is downrange. Keep your finger off the trigger until ready to fire. Don't point your weapon at anything you don't want to shoot. Always ensure there are no unintended targets behind your target such as houses. Is wise to shoot into a backdrop so you always see where the projectile hits.
With this being said you are responsible for your firearm and any damage caused by it.
Step 2: Puttin' 'Er on Paper
This step ensures you will at least hit your target when you start sighting. You can skip this step completely, it just saves ammo.
Start by setting a target at 25yds. You can either use a bore sight and adjust to the red dot or you can do three round bursts. Aim dead center, breath in, slowly release the breath and squeeze the trigger simultaneously. Fire three rounds, adjust your sight/scope, fire three more, etc. repeat this until you have a nice cluster of holes dancing around the bullseye or stop when you hit paper.
Step 3: One for the Money!
Now for the big money. Run out 100yds and set up your target. Get into position, take aim, breathe deep with your stomach. When you go to shoot slowly release your breathe and *Squeeze* the trigger. Don't pull the trigger. It moves the rifle. Fire three rounds. run to your target. Make an imaginary triangle out of the holes and find the center. Adjust off of that center. Your scope will have a scale but its usually 1 click = 1/4" @ 100yds. Adjust your scope and cover the holes. repeat this until you're as centered as you'd like to be.
Step 4: Going the Extra Mile
At this Point I start screwing around to learn my weapon. Pace out like 500yds or go big with 1000yds. shoot your target at this distance. With a Savage 270 Win I had to aim 1' above the bulls-eyes with no wind at 1000yds to hit center.