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If I had to recommend just two books that would help one understand these things with enough depth to not just regurgitate misleading tropes, they would be:
Hasegawa, Racing the Enemy (the view from the politicians, i.e. American, Japanese, and Soviet)
Hersey, Hiroshima (the view from the people on the ground in Hiroshima)
They're both worth reading. The latter can be read in a few days, the former is longer.
OK, I'll give you two different items of interest of wildly differing character.
The first is that the Manhattan Project is in many ways much more remarkable than people give it credit (and people give it a lot of credit). For one, it helps to understand that it took only 8 years after the very phenomenon of nuclear fission was discovered before functional nuclear weapons were made. Overall, the Manhattan Project succeeded not just because it had a lot of resources dedicated to it but because it had a tremendous amount of resources dedicated to it, and a huge chunk of the world's best scientific talent as well. If you were to imagine how a country would go about a nuclear weapons development program you would probably think it would go about like most other programs: do some preliminary research, come up with a design, then build that design. That's not really how the Manhattan Project worked though, and if it had it probably would not have produced nuclear weapons until well after the end of the war. Instead, it was more like half a dozen development programs all run in parallel at the same time, with this costing about as much as you'd imagine something like that costing.
If you were to design a nuclear bomb in 1940 or so you'd probably decide to produce a gun-assembly weapon using Uranium enriched via centrifugation. And this is a pretty solid pick, it's the easiest way to do it today, but it turns out it was actually a little beyond the technology of 1940 to do. The Manhattan Project instead pursued 3 different bomb fuels (2 of which turned out to be feasible), 2 ways of breeding fuel (one of which was workable), 4 ways of enriching Uranium (3 of which worked), and 2 bomb designs (one of which turned out not to be feasible with one of the fuels). It was that shotgun approach which made it even remotely possible to produce bombs by 1945. If they had gone with a more traditional approach where they would have had to course correct every time they hit a roadblock they wouldn't have produced a functioning device until the late 1940s most likely.
Now, point 2:
It's very common to see the nuclear attacks on Japan as being wildly exceptional events, and in certain specific aspects they were, but I think that's a mistake. In more ways than not those events fit in perfectly with the character of the War in the Pacific up to that time. You have Japanese soldiers committing atrocities on unimaginable scales during the war, treating civilians in occupied territories like animals, making sport of killing and rape, and worse. You have the fight against the Japanese home islands. You have a shipping interdiction campaign which is literally starving the entire population of Japan. You have a conventional strategic bombing campaign which is systematically wiping cities off the map. Where firestorms and carpet bombing would kill tens of thousands of civilians in a matter of minutes to hours. Imagine a single person burning alive. Trapped under a fallen house, maybe conscious as they watch the flames crawl toward their body, feeling the scorching heat roast their flesh with no ability to get away, maybe being lucky enough to succumb to smoke inhalation before they are cooked alive. Maybe their gnawing empty stomach rumbles one last time before they succumb to death. Old men, children, women, everyone. Now multiply that times 100,000 in a single day. You know what they call a day like that in the strategic bombing campaign? They call that a Saturday (Operation Meetinghouse, on Tokyo). And they'll do it again on Sunday (Nagoya), Wednesday (Osaka), and then Saturday again (Kobe). And on and on. Like rubbing an eraser across the city blocks and neighborhoods of urban Japan a handful of square kilometers and a few tens of thousands of lives at a time.
That's the context of the War in the Pacific in 1945. And in that context the nuclear bombings were not special. They didn't kill the most people in bombing attacks. They didn't destroy more urban area than other attacks. And despite the novelty of radiation they didn't result in more horrific deaths or injuries than other causes of death in Japan in the war (have you ever seen someone starve to death? have you ever seen burn victims?) Atomic weapons were notable in that they worked in a novel way and unleashed their power all at once and thus were considerably more efficient and reliable (and thus frightening) than conventional bombs. Instead of a third or a quarter of a thousand B-29s crewed by thousands of personnel dropping hundreds of tonnes of munitions over the course of a few hours a single plane with a single crew could drop a bomb with an explosive yield equal to tens of thousands of tonnes of munitions which would unleash its destructive potential on a single target all in one moment.
Dropping the bombs on Hiroshima and Nagasaki were certainly escalations of the war in a way, but in practice they were really only incremental escalations in all but symbolism. Destroying entire cities with such efficiency was a promise of further extensive destruction with equivalent efficiency, which takes away some of the rationalization that one might have while watching cities be destroyed through other means though through great effort. But even if Japan had never surrendered the bulk of the destruction of Japanese cities and the Japanese population would have come through more conventional means. The islands would have continued to be starved and urban areas, and their populations, would have continued to be erased from existence until Japan was utterly annihilated (and perhaps some of it would remain before an invasion was executed).
It's easy to think about WWII as huge stretches of pretty "normal" warfare punctuated by specific isolated incidences of utter brutality (death camps, nuclear bombs, what-have-you), but that's a fiction. Brutality and inhumanity was the norm.