There are a lot of systems. I follow one outlined by Norse nurseries, you can read it on thier website.

Usually for JUne bearers,the new plants are spaced around 12", all blossoms cut the first year, and all runners allowed to root until mid summer. This fills in the rows. Late runners are removed if you have the time as they are unlikely to take and crop the next year.
After the crop, the plants are cut back to the crowns and fertilized.This is called "rejuvenation" and seems very severe when you do it. AT the same time you thin the rows back and weed them out (because you can see everything with the leaves gone. If you don't thin them out they will get so thick as to stunt each other. I aim for a mix of ages to be left behind but want a plant every 4-6" when done.

I was a new strawberry grower 3 years ago, and like you I went crazy trying to do the right thing. I only planted 50 plants and must have had 1500 runners the first year. Last year I had only a few runners, and this year they are going crazy again with runners. I'm not too concerned about next years crop at this point. The soil is good, and there's lots of healthy plants, and as long as I mulch them so they survive the winter I'll see what is growing in the spring and thin accordingly. I stopped watering mine a few weeks ago, but we get lots of rain. Sounds like you'll have a good crop next year. You'll learn alot from your own experience as you go along. The good news is that strawberries grow like weeds.