There are definitely a lot of profession that you can choose from and blacksmithing is one of them. If you decide to become a Blacksmith you will need a Blacksmithing Hammer which you can purchase at one of the trade supply or general good vendors in any of the bigger cities. To begin with you will need to visit your Blacksmith trainer who will learn you this profession and can also teach you to craft new and better items as you go.
As a Blacksmith you will need loads of ore which can be mined from the veins that are scattered all across Azeroth and Outland. Taking these ores for your blacksmith career is definitely not an easy job since you still need to mine these ores, but if ever you want a strategy that will keep you from having loads of ores, then having mining as your second profession can definitely help you because you will do the mining yourself and you will no longer depend on auction for the stocks of your ores considering that their price in auction sales are way too expensive.
Blacksmithing is actually quite easy to level up as long as you have access to the much needed ores. The good thing about learning how to blacksmith is that, you can create new and nice items. The first items that you will create are those weapons and armors. You will eventually learn how to create and craft better plate armor and weapons after several sime of creating the basics of blacksmithing. Plate Armor is worn by Death Knights, Paladins and Warrior which makes Blacksmithing a perfect match for these classes.
As you continue to level up your Blacksmithing you will be asked to specialize yourself in either becoming an Armor Blacksmith or Weapon Blacksmith. You are definitely free to choose whether to specialize in Armor Blacksmith or not, however, if you choose to do so, then you will have different access such as access to the different plans of a blacksmith in creating new and improved weapons. If you do specialize in Weaponry or Armor you will be able to learn several patterns that teach you how to create several rare items. Nevertheless, you can choose either of the two choices since you will still get a lot of benefits in blacksmithing such as creating new and good stuffs that the blacksmithing profession will offer you.