NOTE: This is novelty information and is only useful in an "omg I'm on an airplane and everybody dropped dead except for me" situation. Please don't steal an airplane.
Airspeed is the speed of the airplane relative to the air around it. If you have airspeed then you are flying, otherwise you are falling.
So to land a plane you must remember to always maintain airspeed. Which means you must always be going fast.
Your airspeed will be indicated on the dial above. This is a standard instrument in all airplanes.
If your dial is in the green (or above) you are fast enough to be flying, and not falling. There the fat white line is important if as well but you can land safely without it.
Just make sure to be in the green at all times.
Next step after mastering airspeed is fly towards a safe place to land. Airport runways are great for this.
Fly directly towards the beginning of your intended landing spot. And at all times making sure you have enough airspeed to fly.
As you descend you will want to be gradually reducing power so that by the time you reach your landing spot the power is fully off.
If you are in a small airplane, the power control will most likely be the left most lever or knob in the bottom center of the dash. If you see a lever then push it up for more power, if it's a knob then pulled out is more power.
Note: you will want the red nob or lever set to "full power" during the whole time. This controls fuel flow to your propeller. Keep it wide open.
You want to slowly descend towards your landing spot. Going a little too fast is much better than a little too slow.
Try to keep your airspeed in the lower end of the green area, but always at least in the green area.
If you feel like you are not going to reach the landing spot, then increase power and the plane will level out. Do not try to climb because you will lose airspeed.
If you are to fast (towards the higher side of the green or past), then reduce power slightly. Your plane will start to sink and you will need to raise the nose to keep on track.
Once you are sure you are going to get to the intended landing spot, cut off all the way power.
Fly the plane close to the ground down the runway. It will naturally slow down and gently sink onto the ground. You want to land on your wheels beneath your wings.
You do not want to land on your nose wheel. This will break that wheel and you will crash.
Now that you are on the ground your control wheel will no longer do anything. But your brakes will.
So press the brakes until you are fully stopped. And close the red knob next to the power control. This will cut engine gas and the propellor will quickly stop turning. Also take the keys out.