If large and dense is your jam, The Weimar Republic Sourcebook is a 800 page plus compendium of primary sources about the Republic. The standard English-language survey is Eric Weitz's The Weimar Republic: Promise and Tragedy. Detlev Peukert's The Weimar Republic is a somewhat esoteric survey history. Weimar Thought: A Contested Legacy is a good anthology that serves as an introduction to the intellectual history of the Republic. November 1918: The German Revolution by Robert Gerwarth is a good introduction to the Republic's founding moment. Neighbors and Enemies: The Culture of Radicalism in Berlin, 1929-1933 by Pamela Swett is a very readable account of how violence came to characterize the late-Weimar urban landscape. Jonathan Wright's biography Gustav Stresemann: Weimar's Greatest Statesman is a useful corrective to a number of common assumptions about the Republic's viability. Anna von der Goltz's Hindenburg: Power, Myth, and the Rise of the Nazis is a good examination of the political career of one of the Republics gravediggers. The German Right in the Weimar Republic: Studies in the History of German Conservatism, Nationalism, and Antisemitism edited by Larry Eugene Jones argues that the splintering of the right acted as a segue to the NSDAP's success.