Czech food is hearty, meat-heavy, and built for cold weather. Pork, beef, and dumplings (knedlíky) are the pillars of the traditional diet. It's not subtle cooking, but done well it's deeply satisfying.
The classics
Svíčková na smetaně — beef sirloin braised with root vegetables and served with a cream sauce, bread dumplings, a slice of lemon, and cranberry jam. The national dish in all but name.
Vepřo-knedlo-zelo — pork with dumplings and sauerkraut. Straightforward and filling. You'll see it everywhere.
Guláš — a Czech version of goulash, less paprika-heavy than the Hungarian original, almost always served with bread dumplings.
Bramboráky — potato pancakes, often eaten as street food or a quick lunch.
Trdelník — a rolled pastry cooked over an open flame, associated with Prague and other tourist centers. Despite what the vendors claim, it's not a traditional Czech food — it's a Slovak/Transylvanian pastry that got adopted as a tourist product. Enjoy it if you like, but don't order it thinking you're eating something authentically Czech.
Beer
Czechs drink more beer per capita than any other nation. The Pilsner style — pale, hoppy, bottom-fermented — was invented in Plzeň in 1842, and Czech beer culture has been serious ever since. The main lagers are Pilsner Urquell, Budvar (Budweiser Budvar, not to be confused with the American brand), Kozel, Bernard, and Gambrinus.
A good pub will serve tank beer (tankové pivo) — unpasteurized lager kept in large tanks and served under pressure. It doesn't travel, so drinking it in-country is the point. In Prague, look for Lokál, Pivovarský klub, or any pub advertising tankové Pilsner Urquell.
A half-litre (půllitr) is standard. A third of a litre (třetinka or malé) is available in better pubs.
Wine
Moravian wine is underrated and largely unknown outside the country. The wine regions around Mikulov, Znojmo, and Uherské Hradiště produce good whites — particularly Welschriesling, Grüner Veltliner, and the native Palava grape. Worth seeking out in Brno wine bars or visiting the region during the September harvest festivals.
Spirits
Becherovka, from Karlovy Vary, is an herbal bitter with a distinctive cinnamon-clove character. Slivovitz (plum brandy) is widely drunk, especially in Moravia. Fernet Stock is the Czech equivalent of amaro — an acquired taste but very popular locally.