I use Hacker News. How? When you're reading through threads, people often just mention a book related to the topic at hand. And I check it out.
There are lots of smart people here, and it's reflected in the books they read.
But, while you wait to find books to read, here are some interesting threads for you.
Ask HN: What nonfiction books do you keep rereading?
https://news.ycombinator.com/item?id=40277933
Ask HN: Mind bending books to read and never be the same as before?
https://news.ycombinator.com/item?id=23151144
Good luck. The universe is expanding, read and let your mind expand too!