We have a few good specimens of shark's teeth from Calvert Cliffs. The most amazing find I ever had is when we first moved here and lived in Benedict for a while. The first day that I went to sit on the sand on a blanket by the river, I looked down and an arrowhead was right there; like find me! It was awesome. I gave it to Jefferson Patterson Park for their museum.
Edit: A tip that someone told me was to use a colander and fill with sand, and run through the water that is right there. It works! The same idea as panning for gold. And, you can find fossilized snails and other crittrers, bone, shards of pottery and glass, and other things from days gone by.