I have heard of a book that supposedly 'changed the world' called 'Principia Mathematica' by Sir Issac Newton (est. 1687).
Does anyone know where i could find some more information about it and possibly even give a web address?
Wikipedia has a good article with some links at the bottom of the page: http://en.wikipedia.org/wiki/Philosophiae_Naturalis_Principia_Mathematica
Stephen Hawking's On The Shoulders of Giants talks about Newton's Principia and includes the text. Hawking also talks about Copernicus, Galileo, Kepler and Einstein, and their respective contributions to Physics. The ISBN is 0762413484.
You can shear a sheep many times but skin him only once.
If you'd like more than just information and would like the experience the text firsthand, just visit the bookstore. As All_Is_Number mentioned, Stephen Hawking's text contains the material and it shouldn't be too hard to find at a bookstore. I've encountered it a few times myself. My bookstore also has some edition of the Principia itself, so maybe you could find that too.