Building your Coal Forge

You will need:

Some sort of heavy duty steel drum that will be your firepot. NOT GALVANIZED
A length of pipe to connect to the blower. NOT GALVANIZED
A adjustable blower or some bellows. If you have no adjustment for your blower, use a butterfly valve in your pipe to limit the airflow.
A fuel source, in this case, coal. (If you can find a supplier, use lump coal or charcoal, not the pressed charcoal briquettes.)

You don't want to use galvanized steel of any type, because when it gets up to forging temperatures, it emits a toxic gas that will happily remove your life.

You can use an old brake drum for your firepot, and drill a hole in it to fit the length of pipe.
Secure the drum onto a wooden frame using bolts, make sure it is very secure. If it falls apart when you arw working, 2500 degree coals all over your feet is not a good idea.
The pipe should fit snugly in the drum, and should extend about 1/2" into the firepot.
Connect the blower to the other end of the pipe in a way where you can easily adjust the amount of airflow.
Put a goodly amount of coal into your forge, enough to have a dome shape on top, and light it how you would light a fire, or however you usually do it.
when the coals are going, turn on the blower and adjust the flow rate so that the flames exiting the coal pile are about 2 inches high. After a few minutes, the forge is hot enough to use.

Finding and choosing an Anvil.

 Anvil worthy metal is hard, but elastic. It needs to compress little and bounce back well, all while not cracking or shattering. A good test for determining whether the block of metal could be used as an anvil can be done with a 1" hardened ball bearing. If you drop the bearing from a 1 foot height, it should bounce back up almost to the level which you dropped it. The anvil should also ring pleasantly, almost like a bell, when you strike it.

Finding an anvil can be difficult and time consuming, and if you will only be doing a small amount of smithing, buying an anvil is not a necessity. As long as you have a block of metal that you can pound metal on, you will be fine.

Anything that you use for an anvil needs to be big and well secured to a stand, the heavier, the better. The more inertia that the anvil has, the more the hammer will rebound and the easier time you will have working the metal. A common substitute for an anvil is a section of railroad track. The metal is beaten and hardened from years, sometimes a hundred or more, of supporting train cars. The train tracks can be bought from any metal supply store, or if they are doing maintenance on a railroad near you, you may be able to score a deal with one of the guys.

If needed, you can buy a cube or rectangle of steel from a steel mill or steel supply depot to use as an anvil. You really can use anything, just as long as it is the proper type of metal.