Richard Rhodes' The Making of the Atomic Bomb - a Pulitzer that can be a bit technical at times.
John Hersey's Hiroshima - accounts of survivors

You might check out the book list on the /r/AskHistorians wiki, which includes an annotated section on Cold War technology.

Beyond that — it really depends on what you want out of the topic. If you're interested in strategy, Freedman's The Evolution of Nuclear Strategy is the classic. If it's about weapon systems, it depends on the country. If it's about initial developments, there are many good national nuclear history (e.g. Rhodes, The Making of the Atomic Bomb, or Holloway, Stalin and the Bomb). There are separate good books that look into specific questions relating to, say, missile systems (MacKenzie, Inventing Accuracy), and so on. Lots of sub-topics here, in other words, with lots of books.