There are two basic ways to aim your rifle: iron sights and optics. If you're choosing to "use your irons," that means you're not going to put a scope or reflex sight on your gun. Most hunters find the best success using an optic, because most commercially available rifles can "outshoot" the shooter's ability to see with their naked eyes.
Think about it: How much detail can you see on an object the size of a paper plate at 300 yards? Not much, right? Your rifle can make that 300-yard shot with ease, but you will have difficulty simply because the range of our eyesight is limited. That's why most people scope their rifles ... but it's not the end of the story.
In this great video from our friends at NRA Women, contributor and hunting maven Melissa Bachman explains exactly how to get that scope working for you, from the mechanics of mounting to the simple 1-2-3 of sighting-in.