Preparing For The Nether
The first step of preparing for the Nether is to make sure you have enough materials to build, or dig out, a small home within the Nether. Digging out a home is much easier than building one, Netherrack can be mined quickly with a stone pick, much faster than stone or cobble is mined.
You also want to bring a lot of food and armour, preferably Iron. You will want at least stone tools. Swords aren't that useful in your first Nether visit. Most people won't attack Zombie Pigmen on their first visit, and you won't go searching for Template:Nether Fortress's. So your only real enemy in your first visit will be Ghasts. Ghasts are one of the hardest mobs to fight in minecraft, mainly because of their floating ability and their fireball, which does considerable damage. Unless you're on a cliff and the Ghast is floating in front of you, the only way to take them out is with a bow and arrow. However, aiming and hitting a Ghast is not very hard. They are the largest mob in minecraft and they move incredibly slowly.
Once you have these tools, and enough arrows to take out a few Ghasts you will be ready to...
Enter The Nether
When you first enter the Nether, you may be awestruck by the amazing structure of it, however the Nether is a dangerous place, you will want to dig a small structure and out a Crafting Table and a Chest. Once you have set up your base to your liking, you will be ready to explore