So the sight is pretty basic. It has a 300 yard battle sight (when it is laying down), and when flipped up ranges from 200-1300 yards. You adjust it by turning the screw for the aperture to move up and down (windage is done by moving the front sight left to right).
To use a aperture sight you try to center the front sight post in the middle of the 'hole' in the rear sight. If your not used to it, it can take some time to get used to (I personally prefer the standard notch and post and have a tougher time with apertures, your experiences will vary). I recommend taking out a box or two of ammo, flipping the sight up and setting it at 200 yards and blasting away at 100m until you figure out how the sight works.