be wary of the caverns if you go looking for magma, your dwarves might try and collect spider silk from it automatically and get in trouble with the cavern creatures, or worse, a forgotten beast
i recommend blocking off the caverns and digging down somewhere else until you get though it, that way you dont have to have a security detail around the entrance to them.
military wise, if you have goblins, humans, elves, or necromancers you should plan for war accordingly, while humans and elves wont attack unless you piss them off, goblins and necromancers will attack at any time once you reach requirements
goblins bring leather and copper equipment as well as monsters, elves bring wooden weapons and armor, humans bring various weapons grade materials, necromancers bring armored zombies, ive personally seen copper and bismuth bronze armor but i dont know what else they can wear.
when fighting goblins and elves axes do great, humans armor means that you will need at least steel if you use crossbows (though i personally advise against crossbows due to several issues with them) and spears can pierce their armor, mixed squads of hammer and spear work good. necromancers/zombies should never be fought with swords, axes, spears or other such weapons, maces are the best because a pulped corpse is one that will stay dead, silver maces are awesome. silver can come from tetrahedrite or galena.
as for industry, if you have fire clay you can make stoneware goods which are quite valuable and can be made infinitely, sand allows for glass which can also be made infinitely but isnt as valuable, it is however magma safe.
any other kind of clay can make earthenware, not as valuable as stoneware and also needs to be glazed to be able to hold liquids. they can be glazed with ash or cassiterite. (an ore of tin) if you glaze your ceramics with cassiterite it makes them very valuable, but the glaze is non-renewable. ash glaze is renewable but not as valuable. theres not much use for tin aside from making somebody with a preference for it happy, so using it for glazing is usually a good investment if your looking to produce wealth.
i would also recommend you start up a textile industry, clothing wears out over time and dwarves dont like being naked, plus putting on nice clothes makes them happy. you can use pig tail plants to make clothing.
first have them processed at a farmers workshop, this makes pig tail thread and pig tail seeds, then the thread gets woven into cloth at a loom, and then the cloth into clothing at a clothers workshop.
dwarves will wear whatever you give them, so it dosnt matter if you make dresses or cloaks, at the moment they dont care (though it would be neat if in the future dwarves got a bad thought about being embarrassed for guys being forced to wear a dress XD)
jails and the justice system are a bad idea, your most important dwarves could be arrested or beaten to death for failure to make the 30 adamantine war hammers, or 9001 slade beds that your idiot noble mandates (the 2nd was an exaggeration, but i think somebody had the first one happen)
temples are great, they give massive happiness boosts to non-agnostic dwarves, even just a room with nothing in it will allow them to get a good thought for worshiping, even more good thoughts from the nice stuff you put in it.
danger rooms are also a good idea, but dont go overboard on the wooden training spears, i tried 10 spears per weapon trap before but that resulted in some unlucky blows that took a few lives, one poor guy lost a lot of his teeth, and his left ear. if you stick to 1 or 2 spears per trap you will be fine, the dodging training can massively boost survivability.
another thing, do you have an appraiser and record keeper? they are the two most useful nobles, if you dont, then make an office out of a room with a table and a chair and assign somebody to be both, also turn off all their other labors. record keeping is a full time job and a very useful one at that, it lets you see EXACTLY whats in your fort and how much of it.
theres also a wiki, if you havent been there yet i recommend you take a look at it. also i commend you because it took me 3 months irl just to figure out how to make booze, and that was WITH the wikis help
also, since nobody seems to have given you a proper welcome, allow me
welcome to the bay 12 dwarf fortress forums, please leave your sanity at the door and throw your morals down that bottomless pit in hell.
whether you need to know how to properly torture an elf, or want tips on how to mentally and physically scar your dwarven babies by throwing them into a dark hole with war dogs attacking them for the next 10 years with nothing to eat or drink but what shrooms and booze was thrown in the pit with them when they were born so that one day you can turn them into a vampire wearwolf soldier who will be sent to the circus to fight the onslaught of clowns who are pouring out of the candy buttplug of happy funtime surprises and probably get their face melted off