Noob question regarding materia...

[Diablo-Cyrus]

I've converted a few necklaces into materia... What do I do with it? Can I add it to weapons or armor? If so how? Sorry I'm real new.

[Anapingofness]

No worries.
You can add it to certain gear, but you have to be a crafter of the appropriate level to do so (as well as having done the quest).
So for example, only amorsmith can infuse plate type armor with materia.

Sadly, at low levels materia isn't worth much.
Mainly because of the low caps on gear and the fact that low level materia tends to not have a lot of a stat.

At higher levels, there are certain Materia that are worth more than others because they are used for quests- most notably crafting quests and the relic weapon quests.
DoL and DoH get a *lot* of use out of materia- especially when they hit level 50 and you have to gear them up.

That being said, I would squirrel away said materia on your retainer.

The reason you squirrel away the materia you have now is because you can use it for spiritbonding gear.
Materia infused gear will make the spiritbond gauge fill up faster.
Another thing that will help the gauge fill up faster is if said gear is HQ and if you have the FC buff on. Later, you will get some potions for spiritibonding from a quest that are also really nice.
^^ Hope this helps~

[Diablo-Cyrus]

Thank you, ya right now I'm only level 31 marauder. I plan on going to level 50 with him and then focusing on a crafting skill next. In your opinion what are some helpful skills to go along with a marauder? I unlocked goldsmith.

[Anapingofness]

Marauder and by extension Warrior is one of the two Tank classes in the game (the other being GLD/PLD).
You want to get Gladiator to at least lvl 22 in order to unlock the ability Provoke.
The way Provoke works is that it will give you hate+1. So this is really handy when someone pulls hate and you need to grab it back quickly.
There are also certain fights where tanks have to trade off the mob, and w/o provoke it would be difficult to do efficiently.
You will also get the Flash ability from Gladiator. It's really nice since it helps build hate and it is the only ability that will use up your MP on Warrior.
Convalescence is another good ability. It will increase the amount of HP restored by spells and abilities by 20-30% depending on your level.
Coupled with Bloodbath and other HP regaining abilities that MRD and WAR has, it is a nice effect to have.

You will also get abilities from Pugilist.
Most notably, Second Wind and Featherfoot- there are others you can get but those two are the easiest and at low levels they can be really nice.

Crafting and gear~
The first thing you need to be aware of is that gear you get from dungeons is designed to be better than crafted gear.
The pink gear will be as good as HQ crafted gear.
The green gear is better than pink gear.
Blue gear is better than green.
Later, you will be able to get gear by trading in tomes but that is at endgame.

As far as crafting goes, it becomes more about what you make of it than anything else- because of the aforementioned dungeon gear.
Personally, I enjoyed leveling crafts and the storylines that went with each craft.
That being said-
Goldsmithing is nice since you will be able to make your own accessories.
Amorer will make most of your armor for MRD/WAR.
If you're leveling crafting then you want to invest into Weaver.
I believe Leatherworking makes pants and accessories for DoL.
Blacksmith will make your weapons for MRD/WAR as well as crafting class 'weapons'.
I recommend leveling Blacksmith so you can do your own meld for relic quest. Mind you, you can find others to do it but be careful of people trying to rip you off by charging ridiculous prices to meld materia.
In order to feed your smithing habit, I strongly recommend you throw your lot in with the Miner's Guild.
Being able to gather your own ore and gems is really nice.
If you go for Weaving then I recommend investing some time into Botanist.
You can also make use of your retainer by sending him/her out to gather shards for you if you picked a gathering class for one of them.

The other crafts are nice to have. Especially since there are some cross class abilities that are worth having on your 'main' crafts.
So, I would look into them.

If the prospect of leveling so many crafting jobs is a little daunting- fear not the fastest way to level a craft is by making use of your leves.
Save up to 99 leves, then blow through them.
You will still have to do a lot of crafting mind you, but it will be faster this way.

~_~ sorry for the wall of text

[Urthdigger]

Well, you're going to want to level all of the disciplines of hand (preferably together, as they share all gear except tools up to level 50). This is mostly because of the cross-class skills enabling you to HQ items easier. If you're going to add materia into things, may as well make them as well right? This is especially the case at 50, where crafting is the only way to get higher level gear that can have materia added.

Also, I should add a note about materia caps. Each item has a cap on how high its stats can go. For a high-quality item, the battle stats (strength, intelligence, determination, crit, etc...) will be at their cap. Meaning you can't increase them anymore. Rather, you can use materia to add stats to a piece that doesn't have them. For example, if an otherwise great tank piece lacks +Parry, you can add it.

[Diablo-Cyrus]

This is a lot to understand

[ForteXX]

About stat caps on items (from someone asking specifically about it):

http://ffxiv.ariyala.com/

I believe this site keeps updated materia stat boost limits, but only for battle items.

Click the materia section (if it has slots). If the stat is orange, its at cap. If red, its above cap. If green you can add to it (only useful until it turns red or orange)

This way you can plan ahead what will be useful to add to an item, instead of wasting stats/gil putting a materia in that wont help much.