I'd like to enchant my Daedric armor, however being virgin to the whole enchanting thing makes me wonder how exactly.

Do I need to have a certain enchanting level first? I have a +40 health necklace, how do I transfer it to the armor? Google is giving me complicated answers as if I know what I'm doing to begin with--I don't.

So what's the n00bie explanation?

Visit a enchantmant table, and this allows you to learn enchantments by Disenchanting items, like you necklass, although the item itself will be destroyed.

The same table will allow you to enchant things by choseing an item to enchant, a spell to use and a soul to use from a gem, then it will enchant.

Simple really

enchanting* .. screwed up the topic title.

Does the soul gem have to be a certain size?

The size of the soul gem and your skill effect the strength of your enchant. You don't just wholesale copy a +40 enchant from one piece to another. To do +40 health enchant, you will need skill and perks. And a grand gem.

Tips for the noobie -

Use the Grand Soul Gems to enchant to get the most bang for your buck. I have to buy them with souls for about 1300 to 1400 gold because it is hard for me to find big enough souls easily.
Different items can only be enchanted with certain effects. For instance, the only thing I found to enchant boots is a spell that lets me carry more weight. I could not disenchant a pair of boots that have stealth and are named after the owner that I had to kill. You can not enchant helmets with the same enchantment I used on armor or gauntlets. Bummer. Armor and gauntlets let me enchant some similar effects like fortify health and magic. Helmets seem to let me enchant them with effects that fortify spells like Restoration or Illusion. If you have a lot of cheap jewelry you can make them more valuable by enchanting them using soul gems other than Grand. It doesn't matter what you enchant as you can sell them for more than just plain jewelry. Hope this helps.

Basically, you need to visit an enchanting table and disenchant any magical items to learn their magical properties. I.E if you disenchant a necklace that gives health, you will learn how to enchant +health on other pieces of gear. Disenchanting destroys the item in the process. Then, you select a piece of gear, enchantment and soul gem and select create. (the soul gem must have a soul in it. The larger the soul the more potent the enchantment.) When your skill is low, you will not get powerful enchantments. As your skill gets higher and higher, combined with the best soul gems, you will create the strongest enchantments. Note that not all types of enchantments work on all items.

First place to look is the ingame Help Menus, they explain Enchanting pretty well.

Basically, you need to know the Enchantment, which you learn by Unenchanting something else. Note, this destroys the item, so don't do this on something you need. Second, it does not matter the magnitude of what you unenchant, so pick the weaker of two items if you have it. Knowing a spell does not mean you know the Enchantment of that Spell.

Then, you need an item and a soul gem. Items can only take certain enchantments, like Fortify Sneak can be applied to Boots, but not Armor.

The magnitude of the Enchant is governed by your skill and perks in Enchanting. The size of the soul gem can reduce this magnitude if it is a small soul. Note, Grand Soul gems can have small souls in them, so be careful what filled soul gem you pick.

Does the soul gem determine the number of "charges", i.e. how many times you can hit someone with your frost axe before the battery needs charging?

It does too. It determines the power of the enchantement, and, in case of the number not being high, the number of uses

I also just learned when you use the soul trap spell they have to be alive when you cast it? I had assumed you cast it on a dead body within the time frame of the spell from when they died.