Enchanted Map Scrap - You’ll notice that you’ll find different scraps (¼), (2/4), (¾) and (4/4) and might end up finding duplicates. That’s because these come from chests from different areas of the world. ¼ comes from chests looted in Kryta, 2/4 comes from chests in Ascalon and Dry Top, ¾ comes from the Maguuma Jungle, and 4/4 come from chests in the Shiverpeak Mountains. The wiki link contains more details, but once you have 1 of each, you can double click on any scrap to combine them for a nice reward. I won’t post any spoilers, but you can check the wiki link for a guide.
Encoded Orders - These can be taken to a NPC in Divinity’s Reach to grant you bandit bounties. For more info, follow the wiki link.
Book of Awakening to Light - Once read, it will unlock a collection. You may sell it to a vendor after opening it once.
Black Lion Chest - Containers that have a chance of giving you cosmetic/convenience items from the Gem Store. Follow the wiki link to see what items are currently available from the chest. They do require a Black Lion Chest Key to open. These are obtainable through regular gameplay. For instance, completing the level 10, level 40, and level 60 storylines on a character will grant you a key each. The level 10 one is limited to once a week (Sunday 23:30 UTC-8 is weekly reset), but you can get the level 40 and 60 ones without restriction since they take longer to complete. People often make Key farming characters with the intent of rushing through the level 10 storyline as quickly as possible once per week for a key. Keys are also very rare drops from enemies, are given as a possible reward for getting 100% zone completion, amongst a few other methods.
Hall of Monuments Portal Stone - If your account is linked with your Guild Wars 1 account, you are eligible for exclusive cosmetic rewards. This item allows you to teleport to an area called the Hall of Monuments to pick up your skins. I recommend grabbing all of the skins and then right-clicking them to add them to your wardrobe. Once you’ve done this, you may destroy the Portal Stone to save inventory space. If you ever need access to it again, you may pick it up for free from a couple of NPCs in Lion’s Arch.
Mystic Forge Stone - Save these. They have myriad uses, including mystic salvage kits.For more info about these salvage kits, check my section on salvaging under inventory management.
Aetherblade piece/Key - Destroy them. They’re for a level 80 dungeon path in Twilight Arbor and the keys are dirty cheap. Only buy them when you’re about to run the dungeon path.
Ornate Rusted Key - Used to open Sunken Chests for the Dive Master achievement. You get one after killing 10 Krait. Resets daily.
Tomes of Knowledge - Save these for the spirit shards unless you really want to speed up leveling an alt, but leveling is quick in this game.
Bloodstone Dust - used in crafting ascended gear amongst other things. Eventually you’ll have more of this, dragonite ore, and empyreal fragments than you want clogging up your inventory. At this point, look into getting converters.
Birthday Gifts - If you’re a returning player, your characters receive a birthday gift in the mail each year after they were created. Here’s a breakdown of gifts:
MOST IMPORTANTLY - Look up the dye packs to preview what colors you want OR you can do what I do since I suck at fashion wars and pick the most expensive dyes. Check wiki for prices (ex. https://wiki.guildwars2.com/wiki/Celebratory_Dye_Pack). Scroll down to the bottom to see the other birthday dye packs (3rd through 7th birthday)