They will show you the locations of any and everything worth taking with you. Do you see those blue ores? That’s Cobalt! You can only mine Cobalt at the moment assuming that you have a Molten Picaxe. If not, craft one. Mine the Cobalt, and craft it into bars at a furnance. Craft a drill to be ablt to mine Mythril and if you can also craft a full set of cobalt armor, either with a Cobalt Helmet for melee, Mask for Firearms and Hat for Mana Weapons for increasing the effectiveness of the corresponding weapons. Now mine some Mythril, it’s green. Smelt it into bars and create a Mythril Anvil. Now you can craft a Mythril Drill to mine Adamantite. But you can also make some armor for yourself. Helmet for Melee, Hat for Firearms and Hood for Mana Powered weapons. And now for the last tier... Adamantite. It is very rare, but by destroying a good amount of Demon Altars you will increase your chances with quite a good amount. Now, create a drill so you can eventually craft the best Drill in the game, or Armor, so you can craft the very best Armor in the game. Helmet for Melee, Mask for Firearms and Headgear for Mana. Your almost all decked out. I’d suggest that you begin slaying The Detroyer. There are alot of videos on YouTube on how to do this and HERO will be your guy on how to kill the Hardmode bosses. I can explain you now, but I think it would be better if you’d just watch his videos on how to do it. A good source would be the Terraria Wiki as well. You want to create the Hallowed Armor set (crafted from Cobalt, Mythril and Adamantite armor combined with souls from bosses), Excalibur (crafted from Cobalt, Mythril and Adamantite swords and souls of Might from the Skeletron Prime boss. If you came this far you are guarenteed to aquire all of that Hallowed armor set plus the Excalibur. Thanks for following my guide, and have a good one.