I use a lot of addons that add things to the map. These aren’t strictly necessary but they do save checking wikis etc every 5 minutes. They are all highly customisable so you only show the aspects you need, and you can filter most of these on the map itself, if the map is looking a bit busy 😉
Destinations: I like this addon mainly for the delve boss locations, achievement locations (e.g. the lightbringer), I like M’aiq and the fishing spots (tells you which bait and which fishes still need to be caught). There are other POIs too.
Harvest Map: stores and shows locations of harvest nodes you find.
Lorebooks: shows the locations of the books needed to level up the Mages Guild
Lost Treasure: shows the locations of treasure maps and crafting surveys (rewards from crafting writs)
PublicDungeonChampions: shows the location of the bosses and group events within the public dungeons.
Skyshards: show the locations of skyshards.