I have been reading everything I could get my hands on about the physical realms of our amazing universe. After this wonderful journey I now highly recommend the following books:
(1) The Elegant Universe by Brian Greene
(2) The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos by Brian Greene
(3) Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos by Michio Kaku
(4) In Search of the Multiverse by John Gribbins
(5) The Cosmos by Carl Sagan
(6) A Brief History of Time by Stephen Hawking
I also thoroughly enjoyed the personal diary of an astronaut that went to the moon in the 1960's. A better understanding of spaceship travel with a rocket ship can only help my writing! It is titled Carrying the Fire.