I just rediscovered a website that I haven't been to in years, in is called the Triveno Circle, and is run by James A. Powell. The layout that he has been building is in HO but ideas, styles and basic construction is generally universal in all scales, so I don't discriminate against the other scales except TT, right now it looks silly, but so did N when it first arrived. But anyway his layout is called the Wiscsasset Trivino & Western, it is an excellent layout with many great structures. He has a style that is a little unique, he weathers the pants off of everything and the layout has a very dark undertone. I highly suggest checking it out.
But one of the bonuses of his site is he has many great free signs to download. I have a few examples down below that are from his site. I have had these signs for many years but had forgotten where I had gotten them from, you may notice on a few of my structures I have used these signs, most recently on the Gordon. Just click on the free signs tab on his site for many more to download. Just one note, the signs are at a high resolution so the quality is excellent, you will need to shrink them down so they will be appropriate for N-scale.
So don't just take the signs from here and his site, spend some time looking at his amazing layout and get some great ideas.