If you are considering becoming a weaponsmith, you have probably been to a number of Renaissance Faires and other historical/fantasy events and watched many hours of medieval/fantasy movies. You may also belong to a sword-fighting club and own armour and weapons. Yes, you have become infected with a terrible mental illness for which there is no cure. You have a burning desire to work with hot, sharp things that can fold, spindle and mutilate you and those around you. All you can do is let the affliction run its course.
Acquire training and master the body of knowledge that is essential to weaponsmithing. Take a minimum of two semesters of blacksmithing, metallurgy and design courses at your local high school or community college. You can also take a labour/machine operator position in a machine shop, welding shop or other metalworking facility.
Apprentice yourself to a master weaponsmith that you respect. Weaponsmiths are approached by many people wishing to become apprentices, so don't be surprised if your chosen weaponsmith is less than enthused. According to 20-year master blacksmith Gypsy Wilburn, "Buy one or two of the guy's weapons and slowly befriend him over a few weeks. Be helpful once he invites you to his forge, but stay out of his way. Do not make a nuisance of yourself. Once he shuts down the forge for the day, ask if he needs help cleaning. Leave once things are ready for the next day's work. If you are lucky, he might decide you'll do (Reference 1)."
Buy equipment and materials to assemble your own forge. This is a never-ending process. There is always one more tool to buy or something at the shop to rearrange. Know what is essential to have and stick to the basics. Choose a building for your shop that is fire safe, has adequate ventilation and enough electrical capacity for all of your equipment. If you plan to work from your garage, backyard or other property you already rent or own, buy your equipment according to available space. If you only have single-phase 220-volt service, don't buy 3-phase equipment.
Make weapons. Begin with small, basic weapons such as daggers, knives, tomahawks, hatchets and machetes. Use stock removal techniques and work your way to forged blades. The biggest mistake beginning weaponsmiths make is trying to make a master smith level katana or rapier first. Like everything else worth doing well, you must crawl before you walk and walk before you fly. It is better for both your ego and your reputation to make a good, simple, reliable knife than to make a shoddy sword.
Use your weapons. Give your weapons a thorough shakedown by performing destruction tests. It is better for you to discover a flaw in your workmanship than someone else. Once you are confident in the performance of your weapons, give some to friends or fellow re-enactors and sword fighters. This will help build your reputation. This will eventually lead to requests to make weapons for others, and you will finally have arrived: standing in your booth at your local Renaissance Faire or gun and knife show, behind a table full of weapons you made.
Metalworking, blacksmithing and weaponsmithing are hazardous. Injuries can include lung damage from inhaling metal fumes, cuts, amputations, severe burns and death. Follow correct safety procedures at all times. According to IForgeIron, "Personal safety is taking the extra time NOT to get hurt. Do something differently, call for assistance, do not put yourself in harms way." Always use correct safety gear, including wraparound eye protection, full leathers and face shield appropriate to your project.