For a more serious response, steel is probably the single most useful resource in the game. You can make near-infinite amounts of it, as opposed to cotton candy which has a very limited supply and is a high-risk mining operation. Besides HFS, no enemies have armor that outclasses steel, so dwarves in full steel armor will usually have little trouble fending off sieges (you'll need cloaks to protect their necks, but that can't be made out of steel. Yet). There are two main issues with steel:
1. It is quite heavy, so dwarves who have low armor user skill and a lot of steel armor on will move somewhat slowly, but sparring or danger rooms will quickly rectify that.
2. It can be very resource intensive to create. You have to use two iron ores, 2 fuel, and two flux stones over 4 total smelting jobs to create two bars. If you don't have magma smelters, you'll need another 4 fuel per two bars, which means you'll need 1 iron ore, 1 flux and 3 fuel per bar. If you have access to lignite or bitumous coal, or have a lot of trees on your embark (the caverns help here), fuel shouldn't be too much of a problem. Usually I'll just set a smelter to do "Smelt iron ore R, make pig iron bar R, smelt iron ore R, make steel bars R," which with infinite fuel (wood burners on repeat charcoal, or another smelter making coke) shouldn't be a problem. Another thing to consider is that caravans often bring huge amounts of wood for very little cost and love it when you buy it all off of them.
Anyway, good luck and have Fun with your newfound resource.