Which guilds start in the same town so I can play with my friends

Almost two years after it was announced, the launch of Final Fantasy XIV: A Realm Reborn is almost here. Previous beta players are probably plotting how to best use this Early-Early Access window, since Square Enix has told us progress made during this Open Beta will carry over into Early Access and Launch, but for everyone else there are a lot of questions that still need answers.

What classes can I play and what needs to be unlocked? Which guilds start in the same town so I can play with my friends? When can I start crafting/gathering? Hopefully, by the end of this post I'll have answered everything you need to know to get started in FFXIV and get a head start on everyone waiting for launch day.
Finally there's Arcanist, which I haven't had the chance to play since it was unavailable during the previous beta weekends. According to all of the data mined information, the class is a mix of DoT attacks and debuffs with a pet, Carbunkle, to provide DPS/healing/etc. depending on which version is summoned.
For those looking to play a caster, you have three choices in the Disciples of Magic: Thaumaturge, Conjurer, and Arcanist. Thaumaturge is your DPS caster class - fireballs, frost attacks, lightning and your other typical mage stuff. Conjurer is the healer option for casters - cure spells, cleanses, protection spells and the like. After your character obtain enough mage and xp, you will farm FFXIV gil in fast way!