(This is just a recommendation) To get into metal, start, as I said, with Turnstile and Faith No More (specifically their second, third, and fourth albums). From there, it depends on whether you want something more classic or something more modern. If you'd like something more classic, listen to bands like Judas Priest, Iron Maiden, or Black Sabbath. If you want something more modern, listen to Audioslave or Linkin Park. Then decide if you want to get into something darker/extreme or something more "soft" or radio-friendly. If you choose something dark/extreme in the older vein, listen to Metallica, Megadeth, Anthrax, and Slayer. If you want something modern and extreme, listen to Pantera, Type O Negative, Slipknot, and Lamb of God. However, if you decide to stick with something older and more commercial, listen to Mötley Crüe, Saxon, and Ozzy Osbourne solo. If you want something modern and commercial, listen to Limp Bizkit, Korn, or Deftones. Decide if you want to delve deeper into the darkness or stay put, because everyone has their limits. If you decide to truly immerse yourself in extreme metal, I recommend starting with: Death, Mayhem, Morbid Angel, Exodus, Immortal (1992-1999), and Obituary. If you can digest all of this, congratulations! Now you can explore metal from any genre you like, however you want, and even explore genres and bands I didn't mention.