New guy trying to wrap my head around jobs in this game...

[Gramis]

You might have seen this answer coming, but it's a resounding 'it depends'. Thankfully, you mentioned that you have started to take up mining, so I would suggest blacksmithing, goldsmithing, and/or armorer. Goldsmithing, along with Culinarian and Alchemist, will be getting their synthesis recipes changed in the coming large patch, so until then, I would avoid them. That leaves blacksmith and armorer. I can't really suggest between the two, so I'll just tell you what they're good for and let you pick.

Blacksmiths make weapons and tools. Armorers make shields and armor. There are exceptions to these rules, but for the most part, that's the difference between the two. Which profession you take up is up to you, but I ask... why not both?

For a more general answer, I would say...
Plan on being a fisherman? Culinarian and Alchemist work well with this.
Plan on being a miner? Blacksmith, Armorer, and Goldsmith work well with this.
Plan on being a botanist? Carpenter and Weaver work well with this.
Don't plan on doing any DoL jobs? LTW doesn't rely on DoL jobs much at all. Of course, none of the crafting jobs require a DoL job, and you can level any of them off of monster drops and/or buying stuff, so take your pick! Heck, you don't even have to craft at all!

Fastest way to level DoH jobs is leves and/or regular synthesis at low levels. At high levels (30+) it's fastest to do mostly leves. Don't forget to keep your tools/gear up to date! Crafstmanship/M.Craftsmanship/Control

What do you mean keep you equips up to date... Cuz half my stuff says 'dated'

[Dawiichan]

What do you mean keep you equips up to date... Cuz half my stuff says 'dated'

Dated means that they are items created before the materia patch. Pretty much we'll get to keep them until SE takes them out. I wouldn't be surprised if that'd be soon either because with job gear coming soon, dated gear won't be used as high-end gear anymore(hopefully).

[Conradus]

Dated means that they are items created before the materia patch. Pretty much we'll get to keep them until SE takes them out. I wouldn't be surprised if that'd be soon either because with job gear coming soon, dated gear won't be used as high-end gear anymore(hopefully).

I expect that any dated gear in existence will not be tampered with. You already can't obtain them from as rewards or from vendor NPCs (except for dated accessories, because their replacements haven't been fielded yet). In the coming months, the synthesis recipes for them will be retired and crafters won't be able to make them any more either (you already can't get any new materials for the old-fashioned dyes required to make a lot of them). At that point the dated items will slowly disappear as they are converted to materia, sold to NPCs, or their owners quit the game.

[Dawiichan]

I expect that any dated gear in existence will not be tampered with. You already can't obtain them from as rewards or from vendor NPCs (except for dated accessories, because their replacements haven't been fielded yet). In the coming months, the synthesis recipes for them will be retired and crafters won't be able to make them any more either (you already can't get any new materials for the old-fashioned dyes required to make a lot of them). At that point the dated items will slowly disappear as they are converted to materia, sold to NPCs, or their owners quit the game.

Correct me if I'm wrong but I do believe Yoshi-P said dated gear will eventually be phased out.

[Conradus]

Correct me if I'm wrong but I do believe Yoshi-P said dated gear will eventually be phased out.

Yes. I believe my previous statement is what he meant. They aren't going to want to interfere with items people already possess, but once no more can be created, the ones in existence will gradually disappear through natural attrition.