All The Shah's Men by Stephen Kinzer is a great read that provides a lot of insight into the events leading up to the Revolution, as well as how we got to where we are today.

In an nutshell, the Anglo-Persian Oil Company (APOC, later BP) pillaged oil from Iran, used slave labor, and treated the local population like subhumans. Local parliament got pissed, rose up against the Shah (Mohammed Reza, who was brutal towards his own people while living a lavish life himself, who fled the country and was granted refuge by western powers). Parliament elected charismatic leader Muhammed Mossadeq and effectively kicked out APOC. Western powers (especially UK) was pissed, partnered with the US who used the recently created CIA to carry out their first (of many to come) covert coup to overthrow the new Iran government and reinstate Mohammed Reza (the former Shah). Reza ruled for another 25 years, still the being the dick that he was. Things didn't go well, Shah got sick, made horrible decisions (or sometimes no decision at all), local populace was pissed more than ever and anti-western rhetoric became more and more popular, paving the way for the non-secular government to take hold of the country.