Here, this typically means pils, a light and yellow/gold colored beer. Usually it's served in quite small amounts in order to keep the beer at just the right temperature and taste for you. That's something like 0.3 - 0.4 litres. Pils is the most common beverage here, no matter if you are dining or just having something to drink. Everyone drinks pils - men and women, young or old.
All beer should have a thick foam head on top (two fingers high the Czech - inventors of Pils - say) and be poured slowly and in stages into the glass. If done with care this ritual will take about 5 - 7 minutes! This proper procedure guarantees the best tasting beer.
For some newcomers this lengthy procedure can be confusing: if you didn't know better you might think you are getting slow and bad service, when, in fact, you are getting just excellent service (which equals the best tasting pils).

"Ein pils, bitte" will do as an order even if not correct or beautiful German.

Weizen is a rather special beer brewed of more than 50% wheat which adds a very specific taste to it: slightly sour, fruity and definitely more full than normal beers. It's highly carbonated and hop rates are low.
It usually comes unfiltered with the yeast still inside the bottle, called hefe. Most people like it that way, others order kristall (without yeast). To further complicate the whole thing, weizen also comes in a darker version, called dunkel. (The opposite to dunkel is "helles"). Weizen is usually served in 0.5 liters. Tall, slender, trumpet-style glasses are used.
In summertime it's nice to have a slice of lemon in the weizen - but only for the kristall version.
This type of beer was first brewed because the Duke of Bavaria monopolized the production of barley malt in order to drive up the price. This style of beer is typical for south Germany, and it differs from the other wheat beers around: the American Wheat Beer, the Berliner weisse and the Belgian witbier. How it is different you ask? Try tasting yourself, we cannot tell you everything about beer.

In most countries export stands for any premium type of pilsner. Here it is a style of its own of bottom-fermented beer with a malty taste and less hops-dry than pilsener beers. It is also less dry than normal pils and slightly stronger in alcohol.

An alt is a copper colored and fuller tasting beer. It can be served slightly warmer than other beers. It is top-fermented, like an ale, and tends to have a very pronounced palate where fruity qualities is part of the character. The overall impression is clean, crisp and flavorful.
The German word "alt" means old, but it does not mean that the beer is old or aged for an especially long time, but rather that it is brewed according to an "old" tradition.

A Kölsch may look like a tiny pils, but it is not so. It's brewed by use of top-fermenting yeast strains. These strains perform at warmer temperatures, the ferments are faster and fermentation byproducts are generally more evident.
Kölsch is characterized by a golden color and a slightly dry, winy and subtly sweet palate. The body is light. This beer has low hop flavor and aroma with medium bitterness.
Kölsch is drunk from slim, cylindrical glasses holding only 200 ml. Of course, kölsch is only made in the town of Köln (Cologne). However, it can be drunk anywhere.

Schnaps is something completely different from the stuff in the states.

Ein Schnaps is never sweet, liqueurlike, and always clear. In the southwest of Germany it's from fruit, also in the close Elsass (Alsace) and northern Switzerland. The fruit brings a very light and delicate taste to it.
These three countries are populated by the Alemannen. These are talented hard working and no fun, serious people. They take everything serious, and be it the Schnapsbrennen.
There are two kinds, the Wasser and the Geist. Kirschwasser and Williams (abbreviated Willi) from (Williams-) pears and Pflaume (from plums) and Obstler (from apples) are destilled from the fermented smashed fruit bodies.
The Himbergeist is destilled from (any) alcohol in which the fruit is given for the flavor. My favorite is the Himbeergeist as it's the mildest. Other editors prefer the Kirsch or Willie for their slightly more distinct character. At the end of the day, the differences are not that important, even if we can debate the differences every time we have a small one...

We drink the Schnaps usually after a nice dinner, never alone or before food. The reason for having it after food is that (1) it tastes very good and rounds off the dinner in a nice way, and (2) it aids the digestion process. If you find the German cuisine heavy, a small schnaps post-dinner might help. And, you'll automatically be considered a bit above the rest of the know-nothing hordes of turists when you order a "willi" after dinner... ;-)

The schnaps is served in very small glasses, about 2 cl. This means you can order a couple of them as you slowly digest the dinner. One order at a time of course.

The alcoholics rather have a wodka or a cognac (which is in reality a Weinbrand as we are forbidden to even call cognac Kognak since the peace treaty of Versailles 1919).
(At this stage another guide author - the northern one - loudly objects to categorize vodka as something only for alcoholics! This might be true this far south, but not (way) up in northern europe where vodka is the predominant Schnaps.)

In northern Germany it's a tradition to have a shot of Korn or Kuemmel (like the Jubilaeum (abr. Jubi) or the Linie) along with the (small) beer, in the south not.

Schaps is usually sipped and is served quite chilled. Never mix any water in your schnaps; ice has no place here. Tip: at home, store the bottle and drinking glasses in the freezer. If the liqueur is strong enough it will not freeze (and destroy the bottle).

There's a disagreement among the authors as to if it's ok to drink schnaps "one down" in a single big gulp. Everyone agrees this is barbaric - the disagreement is whether that actually is a bad thing or not.

Schorle is a mixture of white wine and sparkling water, maybe something like 80% wine. Depending on the water ratio, this makes a perfect cool and refreshing beverage on a warm day. It goes well with some lighter food, like sandwiches or cheese.

Mixing water into an already light white wine provides an excellent opportunity to serve really horribly tasting wine. This does not happen too often, although the wine in a schorle is always basic and simple.

If you are a wine snob, you should probably stay away from the schorle.

The area just around town does not produce a lot of wine, but the real (and huge) wine districts are just around the corner. White wine is the most common, and is also known and respected worldwide.
If you have the time, it is not a bad idea to rent a car and visit the "Deutsche Weinstraße" (wine route) in the Pfalz. That is definitely a whole day's trip.

The local red wine is not recognized outside of the area. It is drunk locally and the export is low. If this is caused by the taste of the wine, or if the locals leave very little left to export, is not known.

It must be said that the red wine produced in the region has its own unique style and taste. Compared to french or spanish reds for example, it is much much lighter in taste. The colour is very clear, almost transparent. Quite often there's a fragrance of strawberries and raspberries in the lighter reds. You won't find any tannine rich wines at all.

Not too long ago all places closed at 24.00 in town. This is now changing and more and more bars keep open later, until 2 or 3 sometimes.
One major issue (summertime, that is) is that bars and restaurants are not allowed to serve outdoors (on streets and squares) after 23.00. What this means is that bar owners collect tables and chairs starting at 23.00, but people will still be standing outside of the pubs after that. This can especially be observed on the main square and Unter Strasse.

When entering a pub, decide if your going to stand up or sit down. Most places only have seatings, and hanging at the bar is not the usual thing.
When seated, wait for someone to take your order. There will always be someone who does this - you are not supposed to get your drinks from the bar yourself! Contrary to France, the prices do not vary if you are served in the bar, indoors or outdoors.
Most places don't charge you right away. They expect you to pay when you leave the place, not after each order. In some smaller and more crowded bars this might not be true.

This concept is not really an option, and you have to be pretty desperate to drink your bought stuff somewhere else than in a bar.