I'm not OP, but I just follow my interests. Thankfully, at least with non-fiction, they're fairly broad, so I've read academic textbooks on religion, textbooks on programming, general science books on physics (to complement my textbook knowledge) as well as anthropology, sociology and more. Just find a topic you're interested in, go to Goodreads (I like it a lot more than Amazon for searching books), and see what you can find. Or Google it, and see what trusted people in fields like/recommend. Or even people with interests that align with yours.
As for fiction, I like mostly fantasy, so will browse the shelves and look at hyped books on /r/fantasy, as well as other, lesser-known ones that sound/look interesting (I'm a proponent of looking at covers and titles to see if it seems interesting to look into deeper). I also used to follow some reviewers. For more "literary" fiction, I look mostly at what mainstream reviewers say. I found All the Light we Cannot See that way, and loved it (except for one scene I felt was just completely unnecessary to the novel). Then, perhaps, look for major authors. Umberto Eco is one that comes to mind that I'm fixing to start.
Not OP, but I've read a ~200 fiction books and ~50 nonfiction books over my life.
Usually I pick books by the following:
- If I haven't read a single book for fun, I would pick a popular fiction or nonfiction book. Its a good starting point. Things like "Top 10 books in X category" from goodreads are good examples, or "r/askreddit favorite books"
- After reading 5-10 different books, I'll get a feel for what I like and don't like. I'll search "site:reddit.com similar books to X" and grab recommendations. Compare these to amazon's bestsellers and goodreads.
- For nonfiction books, I generally am more picky. I usually have a list of people I follow, some write reviews on books they read. I have had a few people I respect read "Ego is the Enemy" so I picked that up recently, and its something I struggle with sometimes so it's ideal for me. Nonfiction books are most powerful when you read it at the right time
- For nonfiction more textbook-like books, or something more informational, I usually let reddit / goodreads /hackernews decide what's good and what's not.
I started to read less fiction now, I've seen the same plot rehashed too many times. Nonfiction books are interesting to me at the moment.
I guess it really depends what you want to get out of your book. Do you want escapism, inspiration, or change?
As for fiction, I like mostly fantasy, so will browse the shelves and look at hyped books on /r/fantasy, as well as other, lesser-known ones that sound/look interesting (I'm a proponent of looking at covers and titles to see if it seems interesting to look into deeper). I also used to follow some reviewers. For more "literary" fiction, I look mostly at what mainstream reviewers say. I found All the Light we Cannot See that way, and loved it (except for one scene I felt was just completely unnecessary to the novel). Then, perhaps, look for major authors. Umberto Eco is one that comes to mind that I'm fixing to start.