Enjoy, Kenny!
Just to clarify, "Why Does E=mc2?" is more about relativity than quantum physics, and seeks to explain the properties of this universe, as we currently understand them, while in "The Grand Design" Hawking and Mlodinow take quantum fluctuations as their touchpoint to lead us into a discussion of how multiple universes emerge from our current theories.
Another good read on the multiverse concept is
"The Goldilocks Enigma" by Paul Davies.
Graham