You didn't mention a particular time period, so here are some random recommendations:
- Communist Czechoslovakia by Kevin McDermott is a good place to start for postwar history, and you can go through the footnotes.
- Spartakiades by Petr Roubal is about mass gymnastic performances during the Communist period.
- Making the Most of Tomorrow by Matěj Spurný is about the town of Most, which was demolished and relocated to make room for coal mining during the 1960s and 1970s.
- The Greengrocer and his TV by Paulina Bren is the book that always comes up about everyday life and popular culture during the period after 1968.
- The Struggle for the Soul of the Nation by Bradley Abrams is about political and intellectual culture immediately after World War II.
- Prague by Chad Bryant is a history of the city through the lives of five different people, although I hasten to add that Prague is not the same thing as Czechoslovakia.
- Sexual Liberation Socialist Style by Kateřina Lišková is about sexology, sexual liberation, and gender in Czechoslovakia during the Communist period.