FFXIV resources
Critically acclaimed MMORPG Final Fantasy XIV has a free trial up to level 70 including award-winning expansion Heavensward and the Stormblood expansion with no restrictions on playtime. This covers literally around half of the game, so it's more than enough to see if you like it enough to start paying for it.
The game is available on PC (either through steam or the FFXIV official website, the latter of which is my recommendation), Playstation 4 and 5, and Xbox Series X/S. The global client lets you switch the game between Japanese, English, German, and French. The Korean and Chinese versions each have their own client and servers.
FFXIV Wiki
There are a number of wiki-style game resources out there for FFXIV, this is the one I default to.
Meowlo's FFXIV Quest Archive
An incredibly thorough video archive of pretty much every quest in the game in English, from main story to job quests to optional sidequests hidden in corners of maps. Unlike the average playthrough video, it also shows all the different choices for each quest.
xiv.quest
A text transcript of the game's English version.
German FFXIV
A site collecting translation differences between the German and English versions of the game.
Patch 1.0 archive
An attempt to archive as much as possible of the now-defunct initial launch of FFXIV.
FFXIV Event/Maintenance timers
Shows timers for how long is left to complete daily/weekly activities and when seasonal events or maintenance will end.
Eorzea Collection
A photo archive of all the game's gear items, with filters on which classes can equip it and where to obtain it. Also lets you upload photos of your own outfits and search for user-made outfits using specific items.
Gposerefs
Step by step instructions on how to take reference photos of your character.
Universalis
Collects marketboard information to help find the cheapest prices across worlds.
Garland Tools
Garland Data is a database of all items in the game, including things like how to obtain them and which items share the same model. Garland Bell keeps track of when time-limited things like gathering nodes and hunt marks are available, and FFXIV Fisher keeps track of where and how to catch which fish.
FFXIV Collect
Easily keep track of anything that can be collected in the game, like achievements, mounts, minions, blue mage spells, and so on.
FFXIV Hunt
A site that calculates the optimal route for all your daily hunt targets.
The Lodestone World Survey
Player statistics gathered from public character profiles on the official player site.
The Balance and Icy Veins
Resources on how to optimise your damage when doing high-end raiding.
The PF Strat
A site listing the common strategies used for Savage raids on the NA datacenter.
Ulti Strats
A site listing the common strategies used for Ultimate raids on the NA datacenter.