Blacksmithing is in some ways much the same as Bujinkan. It's basics are simple, a skilled person can obtain great results with simple tools. As in Bujinkan though, the henka to these basics are varied and complex and not what they seem on the surface. The very first thing to learn in blacksmithing is nothing to do with fire, hammers or an anvil.
Stock selection is picking the right piece of steel for the job. What are we going to make, does it need to be high carbon steel as in a sword or mild steel as in a candle holder or horse shoe (modern horse shoes from circa 1900 on were mainly high carbon steel as roads as we know them wore the soft horse shoes out. Prior to this most roads were dirt.)
Types of blacksmiths
Just to continue along this path for a bit longer, blacksmiths do NOT shoe horses. Although a blacksmith can make horse shoes, the art of making and shoeing horses is done by a specialist blacksmith called a farrier. In the days gone by most blacksmiths were also farriers so they shoed horses as well, like petrol stations used to change and repair tyres on cars in times past. There are other specialist blacksmiths as well and other specialist smiths of other types e.g. goldsmiths and silversmiths. Some of the other specialist blacksmiths are: wheelwrights who make wagon wheels, locksmiths who make locks (it is not a smithing art today but was in the past hence the name). Of course the one you all would have heard of the swordsmith who specialized in making swords. There are many more but this will give you an idea of how diverse this trade is. I am what is termed a general blacksmith, which means that I have no speciality, I can do most jobs that I am presented with.
Etymology and working metal
What does the word blacksmith mean? Well black = iron or steel as these are called the black metals. Smith = to hammer into shape, so it is a person who hammers one of the black metals into shape. You may have heard the term "wrought iron" used to describe blacksmiths' work. Wrought iron has two meanings, the first is: wrought iron is a type of iron with zero carbon content that was available in the old days but is rare today (it is the same as mild steel of today although mild steel has up to 0.040 % carbon which is why it is called a steel but it can not be hardened as there is not enough carbon in it.) The second meaning for the term "wrought iron" is wrought is the same as to hammer into shape, Iron is iron no carbon content so wrought iron means one who hammers iron to shape.
Types of steel
Iron is the base metal for steel but for iron to be called steel it must have a small % of carbon in it. For steel to be able to be hardened it must have a carbon content over 0.050%. Steel may also have other elements in it to make it useful for special jobs or applications, for example railroad lines have manganese added to them to make them hard wearing so the trains wheels don't wear it out. Stainless steel has a very high nickel content so that it does not rust. These are just a couple of examples, today there are at a guess some 3000-4000 types of steel maybe more.
As most of the work blacksmiths did in the old days were gates and stair cases, furniture, candlelabras,hinges, etc. etc. , they did not use steel as there was no need to have these things hardened. They used wrought iron so this is why most blacksmiths work is called wrought iron work. They kept the steel to do jobs that required steel as there were only a hand full of different types of high carbon steels then. Steel was used for things like tools, weapons, machine parts, farm implements, etc. So as you can see, stock selection can be a nightmare at times. It is a very important first step to being able to start blacksmithing.
Surgery of steel
How do you tell one lump of Iron from another lump of steel well thats a trade secret ;-)) but generally you dont need to as we have the luxury of steel merchants that sell all types of steel. The most common steel used for weapons is 1084 which is a plain (no extra elements) high carbon steel with a carbon content of 0.084 %. Steel is a funny thing in that if steel which has a carbon content of 1% = 0.100% or over is used to make any thing that takes impact (like a sword or tool) it will shatter into pieces. Thus a very high carbon content in steel is not a desirable thing. I am sure you will now have more questions than I have provided answers but hope this gives you some insight in to the world of blacksmithing.