I never thought I'd be "bigging up" Cambridge University AND Bill Gates, and in the same sentence.
Anyway, the Natural Sciences site for Cambridge University lists useful reading for prospective students. http://www.natsci.tripos.cam.ac.uk/prospective-students/reading
However, the Physics section sends you to this link: http://research.microsoft.com/apps/tools/tuva/index.html#data=3%7C84edf183-7993-4b5b-9050-7ea34f236045%7C%7C
Bill Gates has acquired the rights to a set of Richard Feynman lectures and put them up so that we can all watch them. Hurrah!
You should also find out why it is called Project Tuva - it's another marvellous Feynman story.
