Hi New Dawn,
When I was 12 (almost 50 years ago!) my parents moved us to a new city. Up until that point I was not really a science fiction fan or even a particularly voracious reader. But, in a new city without having made new friends, I was feeling lonely and "dispossessed" and I took to frequenting the local public library. It was there that I acquired a lifelong and passionate interest in science fiction. In those early years, Arthur C Clarke was absolutely my favourite author. I loved the epic scope, the imagination, the essentially optimistic, and humane nature of his stories. The book you're reading (Childhood's End) was one of my favourites but my absolute favourite, which I read many times and influenced me in many ways for my entire life was "The City and The Stars" which is an epic vision of the future of humanity on earth a billion years in the future.
If you like Clarke, I strongly urge you to read his short story collections, especially the old ones which were originally written in the 50's.... there are many stories of astonishingly epic sweep and profound concepts of the "nature of mankind" and our relationship to the universe. collections I recommend include:
Expedition to Earth (1953)
Reach for Tomorrow (1956)
Tales from the White Hart (1957)
The Other Side of the Sky (1958)
Tales of Ten Worlds (1962)
The Nine Billion Names of God (1967)
So many brilliant short stories to read, including these "Must reads" : The sentinel (Which was the basis for the brilliant film 2001 a space odyssey), Rescue party (this one almost a religious experience for me), The star.
I read ENDer's game when it was first published and consider it brilliant. As with Dune and many other good SF novels, the many sequels of Enders Game are not as good as the original
Heinlein I read more sparingly, but I certainly enjoyed Stranger in a strange land. also good is Starship troopers (much better than the film).
In the 50's and 60s'; Clarke, Heinlein, and Isaac Asimov were known as the "Big three" SF writers of their generation/era. Clarke was my favourite. Heinlein tended to write military oriented stories and his right-wing almost fascist views seeped into his stories. Asimov seemed more interested in the hard science of science fiction and was in fact also an accomplished popular science writer. Clarke was the philosopher and idealist of the trio. Kind of like me