Literature prizes are usually the easiest way to weed out what's relatively good and what's not - for example, Brief History Of Seven Killings is extremely good, and it won a few big prizes
Then there's a few sites, including sometimes here at /lit/, Meanjin for Australia, New Yorker & Plougshares for US, Perlentaucher for Germany (amazing meta-page for German lit news, the English-speaking world needs something similar - they basically read all lit and other culture reviews in the newspapers and summarize them in short paragraphs)
As soon as you have developed a taste ( by reading dead white males, like a good boy) you start looking for new stuff, discard the shit and look deeper into the good stuff. Discuss with friends or professors and stuff. You can try to get to know local authors etc.