The first book I checked out was “Your Guide to Cemetery Research” by Sharon Debartolo Carmack. It was one of the only newer books in at the time, so I grabbed it. It was actually very interesting and helpful, even if you don’t plan on doing any cemetery research. She goes over types of stones, types of cemeteries, the different burial ceremonies in each culture, etc. These things will help you pinpoint your ancestors headstone and possibly other information, such as religion and ethnicity.
I recommend it for the genealogy researcher. And you know, we’re always looking for another reason to hang out in a cemetery.