My current fort is trained towards making weapons and armors.
First I look at dwarf preferences via Dwarf Therapist.
Those who like weapons are setup to train weaponsmithing.
For armor, I choose only Shields, mail shirts, breastplate, greaves, and helms. I avoid one boot or one gauntlet moods.
The rest, I determine acceptable stone furnitures: coffers, cabinets, tables, door, thrones. These will be candidates for miners because miners conflict with forges in terms of mood. So these guys become miner, mason, and mechanic.
Engraving also can mess up highest moodable skills.
So, I first setup 4 forges, later expanded to 7 or 8. Each forge is profiled to each dwarf that needs training, and each with it's own work order. Make bolts ~ x32 for weaponsmithing+3 skill.
For armor, I make 3 sets: boots, gauntlets, helm, mail shirt, greaves, and breast plate as they take 10 bars for each set, then I make 2 metal shields. I seem to get 1 armorsmith to 5 weaponsmith.
After someone moods, they are qualified to do other moodable labors that I need such as mining, crafting, leather working, clothier, gems or glass making.
I also have 1 display pedestal to hold the artifact until the maker is trained.
I had one newbie recruit make a steel war hammer, who joined a charge, lost his hammer in the fight, and the undead goblin picked up his artifact and used it against him.
As for kids, they are part of the pool of moodable dwarfs after population 20. Can cheat using DT to enable them labors and go to smithing training via profile also.
p.s. Some dwarfs like pig iron in their preference, and will not begin a mood if a pig iron is not grabbed first. I did not know that you can forbid and allow them to pick another metal after they start gathering. I usually use stock screen and forbid all bars except steel, unless that dwarf likes war hammer and I have platinum bars available.