When I was a kid, I browsed libraries and just read things that looked good. I was literally judging books by their covers.

When I got older, I started relying more upon people. I'd read based on talking to people. Someone would describe a book. If it sounded good, I'd either put it on my TO READ list or just read it. If it was good, I'd look for other books by the same author. I'd also look for similar books/authors.

Other ways of relying upon people are awards. People voted for those books to get the awards-they didn't win them based on some marketing push. Science Fiction/Fantasy has the Hugo and Nebula as the top awards. It's got other significant awards. Most genres have their own awards. There are also general awards for non-genre books. I've not been liked by some books that've won awards, but overall they have been a reliable source of suggestions.

When I was younger, I had clumsier TO READ lists. Now, I use goodreads. It's also good for keeping track of books you have already read. Like a book journal. I write reviews, but mostly for myself. However, goodreads is now owned by Amazon. Since you are starting a new TO READ list, I'd recommend starting a list with a website that is not owned by Amazon. Goodreads will try to sell the books Amazon wants to sell. The will probably restrict exporting your data-which will make changing your website difficult.