Today we have advanced machines to mine iron, but it was not so a millennium ago. How did our ancestors locate the presence of iron deposits, mine them and make weapons out of them? How did they achieve the temperatures required to melt iron given that they didn't have any advanced tools?
Before 1000 BC meteoric iron or occasionally small native iron deposits were worked. These sources are pure iron and can easily be turned into weapons. In Tutankhamun's tomb was found a meteoric iron dagger. Only tiny quantities of such sources are available.
Iron production in significant quantities began around 500 BC. One important source of iron was bog iron which are nodules of iron oxide found naturally at the bottom of swamps. With a rake it is easy to collect them. The Teutons and the La Tene culture, for example, likely used bog iron to make weapons. Bog iron continued to be used right up to recent times. When the American colonies began their iron working industry, bog iron was their first source of ore (see Saugus Iron Works).
The Romans were the ones who really geared up, producing large quantities of not just iron, but steel. This was a key factor in their success. They had various sources of iron ore, possibly including Latium itself (which was very swampy), but the big key source was the island of Elba. On Elba are extensive, pure deposits of hematite (actually specular iron) which have been worked all the way up to modern times. Hematite is pure, concentrated iron oxide and is an excellent iron ore. Elba had been developed even before the Romans by the Etruscans, but when Rome took over they greatly expanded the mining operations there.
To make steel the Romans used simple bloomeries of a type that later became known as a Catalan forge. This type of forge was used for thousands of years. In fact, even today backyard blacksmiths make steel using the Catalan forge. It is quite tricky to become good at using such a forge, but once the technology is mastered it is easy to make good quality steel.
Anatolia is often credited with being the birthplace of ironworking. Ironworking precedes the Hittites, dating back to at least the third millennium BC in Anatolia, but the Hittites made important advances in metallurgy. Unfortunately, we know very little about the origins of metal working. Archaeological finds are very rare: because metal was so valuable, artifacts were not likely to be lost or discarded. What little we do know comes from the written records:
Hittite scribes paid little attention to the metallurgical procedures itself. From isolated notes it can be concluded that the raw material was first sorted. Melting was described with the verb zanu- (to cook) . . . The application of purification processes might be inferred from the fact that different qualities of metals are mentioned. The skill of alloying is attested by texts describing the production of gold – copper alloys and, of course, bronze. The metal was cast (lahuwai-) into ingots or finished products. From an ingot or talent the necessary quantity was broken off (arha duwarnai-), in order to recast (appa lahuwai-) it into final products.
In the case of iron, according to the terms used, three production stages can be observed: ‘the iron directly (taken) from the furnace’ (AN.BAR S A KI.NE), the standard product ‘iron’ (AN.BAR), and the higher quality, probably more highly valued ‘excellent/first-class iron’ (AN.BAR SIG). The final product might have been iron ingots, bars or blades. State-owned iron smithies are attested by the famous letter KBo 1.14 of Hattusili III to an Assyrian king. On the other hand, 56 iron blades and 16 clubs of black iron mentioned in a tax list 24 show that iron was also produced by provincial communities. (source)
The authors note that regular iron was attested to before meteoric iron. The Hittites did not seem to value one over the other, treating them as functional equivalents.
Unfortunately, it seems like the origins of metallurgy and most of the truly ancient mining and smelting techniques are lost to time.