Early on I just did experiments. I let doughs go for long periods of time and also used them early just to see the extremes. There is no "perfect time", just perfect for you. Now I generally know by the amount of time, if I dont like when im doing an experiment I can tell by poking the dough. The feel of it and the reaction of the dough will tell me where its at in the process. I hate do do this but I will quote what I said yesterday.
This is where experience comes in. The more pies you make the more experience you have with dough "feel". Many times you can just feel what it needs or wants, when its done kneading, when its done fermenting.
Make alot of pies brother, the more you handle the dough and start to understand whats going on the better your pies will be as will your understanding of how all the different pieces of the puzzle fit together.
Not long ago I was in your shoes, when I first started I had zero experience baking...literally. Pizza was the first thing I ever attempted. I was in way over my head and would read 90% of the stuff on this board and have zero clue what people were talking about.
Patience, reading, asking questions all helped out. But the biggest thing IMO is experience. When you start making alot of pies and you get that experience, you start to see and understand many of the things you read about. Flour and water is cheap. Experience is golden.
I guess this is of really no help to you directly as far as your question asked but realize that much like sex, you can read about it all you want but its not until you do it that everything makes sense."