About knocking on doors - yeah, it's a humbling experience. There's no trick to it, other than being extremely polite, apologetic, and being ready to jump back in your car in case the farm guard dog is the only one that comes to meet you.
I don't think there is any official policy on stalking or setting aside of areas, but my guess is that the administrator will let you know who is where and set out some guidelines to keep you and the other clients happy.
Call them up - I'm sure they will be happy to try and answer your questions.