Hey /r/AskHistory,
I found some interesting articles about first atomic bombs and it looks like a huge undertaking. Could you recommend a book (preferably) or some consolidated resource where I could find the complete story, in a friendly way?
What I would be interested: How did the idea take shape in the first place? How was president Roosevelt convinced to start this and also allocate money? How much money were spent for this? What were the technical challenges in the way?
The standard popular source is Richard Rhodes, The Making of the Atomic Bomb. It won the Pulitzer Prize in 1988. There are newer books that flesh out different aspects that have been written since then, but it's still a good place to start.