Tutorials/Defeating a Nether fortress

Nether fortresses are dangerous for unprepared players, as they have many dangers, including blazes, wither skeletons, dangerous falls, and many rooms that are easy to get lost in.

Reasons for defeating a nether fortress
There are several benefits of defeating a nether fortress:
 * To get blaze rods, essential for brewing and crafting several interesting things, including Eyes of Ender and Ender Chests.
 * To set up a blaze farm or/and a wither skeleton farm.
 * To get wither skeleton skulls to summon the wither or for decoration.
 * To gather nether wart, also essential for brewing.

Preparations
Preparing before you even enter a nether fortress is essential. Some recommended items are listed below:


 * At least an iron sword. Your melee weapon is absolutely essential while exploring a nether fortress. An iron sword will do, although a diamond sword is recommended. If you have access to enchanting, try to get Sharpness or Smite, Unbreaking, and Looting (for more wither skeleton skulls or blaze rods). Knockback is mediocre and Fire Aspect will be (almost) useless in the nether due to widespread fire immunity.
 * A bow. A bow allows you to take out enemies above the ground or inaccessible from your current position. Blazes and Ghasts fly quite often above the ground. For enchantments, get Power and Unbreaking. Infinity is also good to bring. Punch is much less uesful as most mobs you will be shooting at are far away and a small knockback makes little difference. Flame will see almost no use.
 * At least a stack of arrows
 * At least a full set of iron armor
 * A diamond pickaxe
 * At least 1 golden apple
 * Highly nutritious food, such as cooked porkchop or steak
 * At least two stacks of cobblestone
 * At least a stack of torches
 * A crafting table, a chest and  a furnace to set up a temporary base
 * A crossbow (optional)