If you want to understand the collapse of the Weimar Repulbic, you have to start at the beginning, with the (failed) revolution. To give a rough sketch of the context: In the war there were the so called Burgfrieden politics of the social democrats (SPD), which meant that the SPD and it's unions would support the war effort by voting for war credits and by not striking. This decision split the SPD; on the one hand the right wing majority, on the other hand the anti-war left and center wing, which founded the independent social democrats (USP) and radical left groups, which after the war would found the communist party (KPD).

In the revolution worker and soldier councils mushroomed everywhere and were dominated by the SPD. At the General Council Convention in December the relation of SPD delegates to the left wing delegates was 7:2. The convention decided three things: it wants a parliamentarian democracy, a new democratic army instead of the old militaristic one, and socialization of "ripe" industries.

At the same time the new interim government, dominated by SPD leaders like Friedrich Ebert, wanted mostly to maintain order. It feared a left wing coup like in Russia the most. Only days after the revolution it decided to build alliances with the old order: the Ebert-Groener alliance with the old army and the Stinnes-Legien agreement between the unions and the big industries. And it began to build up paramilitary units to fight the left: Freikorps, Sicherheitswehren, ... Most of the recruits were officers and front soldiers, who were disenfranchised by the revolution. In 1919 the government used those units against uprisings in Berlin (with over 1200 dead); against the "council republics" in Bavaria(over a thousand dead), Bremen, Mannheim, Braunschweig; against wildcat strike waves and uprisings in the Ruhr-area.

Those Freikorps were the rallying point for people who did not like the new order and around those units groups formed who wanted a right wing coup. But they weren't really sure about the when and how. Exactly one hundred years ago they thought that now is the time, because the allies wanted the disarmament of the Freikorps and especially of the Freikorps in Berlin. Those were the core military units of the coupist, so they started the Kapp coup. But they had no mass support. A big general strike began against the coup and a lot of workers armed themselves to fight the coup. The coup failed after four days, but the armed uprisings did not end that fast. So the reinstated SPD-lead government send the coupist Freikorps to put down the uprisings; hundreds of workers died. The usage of those Freikorps, which often used the swastika as their symbol, by th SPD sped up the disenfranchisement of large parts of the working class from the SPD, which lost a lot of it's base. On the other side a lot of Freikorps soldiers went on to join the movement which would become national socialism.

So the (quite violent) aftermath of the revolution created a factionalised and polarized Weimar society, which could not overcome it's differences. Obviously what I wrote is quite rough sketched in broad strokes; it can only be a motivation to look into those events. I don't know a lot of English literature, but one book, which tries to tackle that phase and which is quite accessible is "Founding Weimar" by Mark Jones. (Sorry for my bad English.)

Studied this in high school and I think a really good place to start for basics on why the Weimar Republic collapsed and how the whole system contributed to the rise of the nazis is; Weimar & Nazi Germany: The Schools History Project

It’s covers all the way from the creation of the Weimar Republic up until the fall of the Third Reich. I think a really important contributing factor to the fall of the Weimar Republic would be the implemented voting system. Democracy was new to unified Germany, and they very much messed up how parliament was elected/structured. You had proportional voting for the lower house (meaning it was hard to have a one party majority, and there were always minority parties), and the issue here is that how can you set up a majority government in the lower house (where it’s supposed to be derived from) if the voting disallows for a two-party majority system? I think there were a lot of other contributing factors (the Great Depression, loss of WWI and the stipulations of the Versailles Treaty), but the voting system was also a major factor.

From 1928-1933 until Hitler’s appointment as Chancellor by President von Hindenburg (who had the power to appoint a chancellor in the event of a lack of clear leader in the lower house), Germany had four federal government elections, more so than if they had instead used preferential voting for the lower house.

But anyways the above book is really helpful, because if you don’t have a good understanding of the different types of voting and the structure and origin of the Weimar Republic, this is really good place to start.