After a while, an American in Germany will come around to this topic of schnapps. It's basically a German definition of a distilled drink. Usually, it's from cherries, apples, pears, or plums. There are other choices....but these are the bulk of choice.
Apfelkorn? It's a apple drink of sorts....up in the higher numbers of 30-proof range.
Himbeergeist? It's a raspberry drink.
Goldschlager? It's a cinnamon-flavored liquor.
I would imagine there are a minimum of three hundred varieties over Germany.....with countless other garage or basement-created versions as well.
The general advice I'd give is that you probably want to limit yourself to three of these, and try to stay more toward beer or wine. After a big meal at a pub or restaurant.....the waiter may come around and offer you a small free glass as part of the deal (more likely to be found at Greek or Italian places than German). It'll be a very small glass and there's no worry about getting a bit tipsy over that one glass. Its the ones that come after that.....that you need to worry about.