Eggs prepared 'over easy' (sometimes called 'over light') are cooked on both sides lightly enough so that the yolk is runny and the surrounding egg white is soft.
It's a common method of preparing eggs in many countries (with many regional variations of course), but the basic preparation isn't terribly difficult.
The secret lies not in TIMING but rather in watching how the appearance of the egg changes during cooking and getting a feel for the right time to flip it so you get the consistency you like.
If needed, lightly spray your pan with light cooking spray. You don't need butter or heavy oil. I like to get under my eggs easily, so I'll lightly spray a non-stick pan for extra lubrication.
Preheat stove. On mine, I use a medium / high setting. You don't need it too hot; we don't want the egg too cook too quickly.
Here's the first secret: notice how an egg is made up of three separate layers. 1) a very thin "under white" 2) a thicker layer of egg white 3) the egg yolk.
You want to watch layer # 2. Watch for when it starts to turn opaque. For contrast notice the egg at bottom is further along than the egg at top.
How opaque you let the egg white get is a matter of taste. I like mine fairly runny so as soon as it starts to thicken I make my move...
It takes practice to flip your egg without breaking the yolk; you'll develop a feel for it.
Using a good, stiff spatula, get under the egg at the yolk and gently flip it. This egg is now upside down in the pan.
Just be slow and gentle and really try to lift the egg by centering the yolk on your spatula so the weight is fully supported. Flip slowly and gently so the yolk doesn't break on landing.
Now for secret # 2: remove the pan from heat. The residual heat of the pan is all you need to cook the top side of the egg.
Staying on the hot ring will almost certainly overlook your egg. I let mine sit for 20-30 seconds in the hot pan, but over a cold element.
Transfer from pan to plate (flip it back to right-side-up on your plate) and garnish with a little salt, pepper and add some parsley flakes for presentation.
Mmm. Yummy eggs over easy. Enjoy!