Any book suggestions for me?

If you like Heinlein you should totally pick up some more clic sci-fi. I'd recommend Isaac Asimov's I, Robot first - ignore the movie, it was funny but in a final ysis a total ization of Asimov's work. Also, stories by Ben Bova, Philip K. , and Jerome Bixby are excellent. Although I haven't read any of their work, Orson Scott Card, Harlan Ellison, and Arthur C. Clarke are all well-regarded in the science fiction community.