Book: Asimov's 'End of Eternity'

This is a very interesting book, the first time I read this book (a fairly small novel), the concept struck me as pretty awesome. After I returned the book from where I had borrowed it, I just had to go and buy it (off eBay).
Isaac Asimov is very famous for his science fiction novels, and very famous for his Foundation and Robot series. This is a novel that has not somehow become that famous, and the story can be a bit complex.
Enough description about the book, here is a brief synopsis of the book:
In the future, mankind has learnt how to do time travel. With time travel comes the responsibility of making sure that changes made by the nature of time travel are controlled (for example, nobody should be able to go back earlier in time and make changes that have a colossal impact). So an entire organization is setup called the 'Eternity' which control the time changes allowed. This organizations exists across the centuries and only they control the movement in time up and down. When it is seen that a major war is about to break out or other similar disaster, the 'Eternals' calculate what is the basic minimum change required in an earlier time period so as to avert the disaster and go and make the change, thus preventing a disaster from happening.
The premise of the novel is that such changes prevent the natural development of humankind of innovation and technological growth (as an example, a prototype of a spacecraft goes disastrously wrong and the option is to remove this development from earlier in time). It may be cruel, but humans develop through adversity and through mistakes, and if these are removed, development also reduces. In the end, humankind never manages to move out of the home planet because the development of fast space travel never happens.
The novel moves to a place where there is a single person who can make Eternity continue or disappear, and he has to consider all these above facts before making the decision.