Simple instructions on how to bore sight your rifle:

How to bore sight a rifle by Chuck Hawks

If you are new to shooting and don’t know what bore sighting is then I recommend reading the article. Bore sighting allows you to more or less sight your scope (align the cross hairs with the point of impact at a certain range). Then when you get to the gun range you at least know you will hit your target. You can then adjust the scope by seeing where your shot went and changing the windage/elevation accordingly.

Laser bore sighting devices can be purchased to help with bore sighting:

From opticsplanet.net:

Measure 25 yards, you may use a vice or gun rest to assist in holding your weapon on target. While the laser is on the bull’s eye, you can now observe how many inches your scope or iron sights off target (the laser will put you within 1.5 to 2 inches of dead center).