This is still a contentious issue, but the go-to popular account is "All the Shah's Men" by Kinzer. Just be warned that its overall approach to Iranian history is from a pretty pro-nationalist perspective, and to call it a hagiography of Mossadegh is... an understatement. My sense is that it's intended as a counterpoint to mainstream pop history explaining everything in terms of American and British interests and perspectives (and a particular set of capitalist and neoliberal values and assumptions) but at times it reads like a parody.

I know I sound super negative, but I still think it's a good overview if you take the tendentious parts with a pinch of salt.