I had one done over 13 years ago, it became apparent after upping my mileage up too quickly when i tried running back then. As i hadnt actually been running all that long I didnt end up taking it up again and did other exercise.
I have tried running a few times since and would always go out and run for as long as i could, usually first run about 20 mins and would build up over a couple of weeks to 35 mins and my knee would hurt again so i would give up.
This time i really wanted to do it as a friend at work was doing the couch to 5k, she was getting on so well, and especially as she had never run before. So i decided to start at week 5 and build up gradually. It was a few weeks before i felt my knee and it wasnt too bad so i would ice it during the evenings and make sure i got my rest days in. I am now up to 10k and it sometimes aches a bit but i again ice and rest it and so far so good. Take it steady and dont run on it whilst its hurting, i think a golden rule is to listen to your body. Good luck