In this thread I'll try to keep up to date with all FAQs posted (they do this over time) on the Lodestone frontsite. If you're wondering what the Lodestone website is, it's the official FFXIV website.

FAQ: Maps, Enemies, and Ranks
FAQ: The Interactions Menu & Guildleves
FAQ: Getting Around
FAQ: Combat & Battle Modes
FAQ: Gathering
FAQ: Bazaars
FAQ: Actions
FAQ: Trading and Using Items

If you have any questions about playing the game that aren't answered by reading the above links, feel free to ask in this thread!