I think trying to inform all residents by flyer, etc could lead to bigger problems with people claiming they didn't receive proper notification. I would stick to putting up a large sign at the entrance.
Some people will still not "see" it. I had a case years ago in a complex I managed - a guy who was renting a space hadn't paid his rent and I couldn't contact him by phone. I put a note on his windshield 3 times asking him to call me, giving my number, etc, all ignored and next week he's on the phone ranting about how dare I have him clamped without even warning him!