Nether Creatures

The Nether, in my opinion, is an extremely annoying obnoxious excuse for something that is so hard to reach. The only rewards are some glowing stones and light-able blocks. You can make it somewhat more enjoyable by having some background knowledge on the monsters that dwell within.

The Ghast
A flying menace, it has the ability to shoot fireballs. These fireballs vary on strength, but are deadly and can destroy bloodstone. It's imperative to your survival that you put up some kind of wall. Cobblestone is the best. Dirt has a chance of breaking once shot at, but cobblestone doesn't. The best two ways to deflect the fireballs is to either shoot the fireball with an arrow, returning it to it's sender, or switch into 3rd person. The ghast aims at your camera. So it aims at you in 1st person, but will shoot aimlessly above your head in 3rd person.

Zombie Pigmen
Zombie pigmen are neutral mobs. Don't attack them. If you attack them, the whole group will swarm you. At that point your chance of survival becomes very slim. If you do engage, make a temporary home to get some height on them If you manage a kill there drops are 0-2 cooked porkchops, effectively making a renewable source of food within the Nether.