When posting your "For Sale" signs and any other signs connected with your real estate business and listings, know the rules. Real estate being very local, PLEASE check with your own municipality (local or state) as to whose rules you need to follow.
In Delaware, it's DelDot, the Delaware Department of Transportation. I know about the rules because one of my signs was supposedly in violation of the rules. When I went to retrieve it (yes, with my money in hand), I asked for a copy of the regulations. I was directed to the statute, which you can read here:
Be careful in your area about Open House signs and directional signs. Here in Delaware, you're not supposed to have signs left in place that guide you to a house. DelDot sort of puts up with our Open House signs, though I have heard of even some of those being confiscated, but standing directional signs... the ones that basically say, "Hey you! Look! There's a house for sale. Right there. See it? Down the road? This way!" are not allowed.